8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reported): September 13, 2006

NorthWestern Corporation

(Exact name of registrant as specified in its charter)

Delaware (State or other jurisdiction of incorporation)		0-692 (Commission File Number)	46-0172280 (IRS Employer Identification No.)
125 South Dakota Avenue Sioux Falls, South Dakota (Address of principal executive offices)			57104 (Zip Code)
	(605) 978-2908 (Registrant’s telephone number, including area code)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions (see General Instruction A.2. below):

o Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 1.01 Entry into Material Definitive Agreement.

On September 6, 2006, NorthWestern Corporation (the “Company”) entered into a purchase agreement (the “Purchase Agreement”) under which it agreed to sell $150,000,000 aggregate principal amount of its 6.04% First Mortgage Bonds (the “Offered Securities”) due September 1, 2016 with Credit Suisse Securities (USA) LLC and Deutsche Bank Securities Inc., as representatives of several initial purchasers (together, the “Purchasers”). The Purchase Agreement is filed as Exhibit 10.1 to this Current Report on Form 8-K, and the descriptions of the terms of the Purchase Agreement and Offered Securities in this Item 1.01 are qualified in their entirety by reference to such exhibits.

The closing of the sale of the Offered Securities occurred on September 13, 2006. The Offered Securities have not been registered under the Securities Act of 1933, as amended (the “Securities Act”). The Company offered and sold the Offered Securities to the Purchasers in reliance on the exemption from registration provided by Section 4(2) of the Securities Act. The Purchasers then sold the Offered Securities to qualified institutional buyers pursuant to the exemption from registration provided by Rule 144A under the Securities Act or non-U.S. persons pursuant to the exemption from registration provided by Regulation S under the Securities Act. The Company relied on these exemptions from registration based in part on representations made by the Purchasers in the Purchase Agreement.

The Offered Securities will be issued in fully registered form, in denominations of $1,000 and integral multiples thereof, and will be available initially in book-entry form only.

The Offered Securities will pay interest semiannually in arrears at a rate of 6.04% per year. Interest is payable on March 1 and September 1 of each year, beginning on March 1, 2007. The Offered Securities mature on September 1, 2016.

The Offered Securities were issued under the Mortgage and Deed of Trust, dated as of October 1, 1945, of the Company, pursuant to the Twenty-sixth Supplemental Indenture, dated as of September 1, 2006, between the Company and The Bank of New York and Ming Ryan, as trustees (the “Trustees”) (the “Indenture”). The Indenture is filed as Exhibit 4.1 to this Current Report on Form 8-K, and the descriptions of the terms of the Indenture and Offered Securities in this Item 1.01 are qualified in their entirety by reference to such exhibits.

The Offered Securities will rank equally in right of payment with all current and future debt that is secured by the referenced first mortgage lien.

The Company may redeem some or all of the Offered Securities at any time at its option prior to maturity.

The Indenture provides for customary events of default, including payment defaults and certain events of bankruptcy, insolvency and reorganization. If an event of default occurs and is continuing, the principal amount of the Offered Securities, plus accrued and unpaid interest, if any, may be declared immediately due and payable. In addition, under certain circumstances, and to the extent permitted by law, the Trustees may be granted certain powers to take possession of, hold, operate and manage, and sell, the mortgaged property.

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Holders of the Offered Securities are entitled to the benefits of a Registration Rights Agreement, dated September 13, 2006, among the Company and the Purchasers (the “Registration Rights Agreement”). Under the Registration Rights Agreement, the Company has agreed to file a registration statement with the Securities and Exchange Commission registering an exchange offer or the resale of the Offered Securities under the Securities Act. In the event the Company fails to satisfy such obligation, it may be required to pay additional interest. The Registration Rights Agreement is filed as Exhibit 10.2 to this Current Report on Form 8-K, and the description of the terms of the Registration Rights Agreement in this Item 1.01 is qualified in its entirety by reference to such exhibit.

On September 14, 2006, the proceeds from this offering, along with cash on hand, was used by the Company to repay the entire $150,000,000 in principal amount of its 7.30% First Mortgage Bonds due 2006, which were due on December 1, 2006, and all related fees, expenses and premiums. Expenses related to this offering are estimated to be approximately $2,000,000 including the make-whole premium, underwriting fees, and legal and accounting expenses.

Item 2.03 Creation of a Direct Financial Obligation or an Obligation under an

Off-Balance Sheet Arrangement of a Registrant.

The disclosure required by this item is included in Item 1.01 and is incorporated herein by reference.

Item 8.01 Other Information.

On September 13, 2006, the Company issued a press release announcing the closing of the sale of the Offered Securities, a copy of which is attached hereto as Exhibit 99.1 and incorporated herein by reference.

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Item 9.01 Financial Statements and Exhibits.

(d) Exhibits

EXHIBIT NO.	DESCRIPTION OF DOCUMENT
4.1	Twenty-sixth Supplemental Indenture, dated September 1, 2006, among NorthWestern Corporation and The Bank of New York and Ming Ryan, as trustees.
10.1	Purchase Agreement, dated September 6, 2006 among NorthWestern Corporation and Credit Suisse Securities (USA) LLC and Deutsche Bank Securities Inc., as representatives of several initial purchasers.
10.2	Registration Rights Agreement, dated September 13, 2006 among NorthWestern Corporation and Credit Suisse Securities (USA) LLC and Deutsche Bank Securities Inc., as representatives of several initial purchasers.
99.1	NorthWestern Corporation Press Release, dated September 13, 2006.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

	NORTHWESTERN CORPORATION
By:	________________________________________
	Thomas J. Knapp
	Vice President, General Counsel and Corporate Secretary

Date: September 14, 2006

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Index to Exhibits

EXHIBIT NO.	DESCRIPTION OF DOCUMENT
4.1*	Twenty-sixth Supplemental Indenture, dated September 1, 2006, among NorthWestern Corporation and The Bank of New York and Ming Ryan, as trustees.
10.1*	Purchase Agreement, dated September 6, 2006 among NorthWestern Corporation and Credit Suisse Securities (USA) LLC and Deutsche Bank Securities Inc., as representatives of several initial purchasers.
10.2*	Registration Rights Agreement, dated September 13, 2006 among NorthWestern Corporation and Credit Suisse Securities (USA) LLC and Deutsche Bank Securities Inc., as representatives of several initial purchasers.
99.1*	NorthWestern Corporation Press Release, dated September 13, 2006.

* filed herewith

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EX-4

NORTHWESTERN CORPORATION

TO

THE BANK OF NEW YORK

AND

MING RYAN

As Trustees under Mortgage and

Deed of Trust, dated as of

October 1, 1945, with NorthWestern Corporation

_______________

TWENTY-SIXTH SUPPLEMENTAL INDENTURE

Providing, among other things, for First Mortgage Bonds, 6.04% Series due 2016

_______________

Dated as of September 1, 2006

TWENTY-SIXTH SUPPLEMENTAL INDENTURE

_______________

THIS TWENTY-SIXTH SUPPLEMENTAL INDENTURE, dated as of September 1, 2006, between NORTHWESTERN CORPORATION, a corporation duly incorporated and existing under the laws of the State of Delaware (hereinafter called the “Company”), having its principal office at 125 S. Dakota Avenue, Suite 1100, Sioux Falls, South Dakota, 57104, and THE BANK OF NEW YORK (hereinafter called the “Corporate Trustee”), a corporation of the State of New York, whose principal corporate trust office is located at 101 Barclay Street, New York, New York, 10286 (successor to MORGAN GUARANTY TRUST COMPANY OF NEW YORK (formerly Guaranty Trust Company of New York)), and MING RYAN, whose post office address is c/o The Bank of New York, 101 Barclay Street, New York, New York, 10286 (successor to Arthur E. Burke, Karl R. Henrich, H.H. Gould, R. Amundsen, P.J. Crowley, W.T. Cunningham, Douglas J. MacInnes and MaryBeth Lewicki) (said Ming Ryan being hereinafter sometimes called the “Co-Trustee”, and the Corporate Trustee and the Co-Trustee being hereinafter together sometimes called the “Trustees”), as Trustees under the Mortgage and Deed of Trust, dated as of October 1, 1945 (hereinafter called the “Mortgage” and, together with any indentures supplemental thereto, the “Indenture”), which Mortgage was executed and delivered by The Montana Power Company, a corporation of the State of New Jersey (hereinafter called the “Company-New Jersey”), as indirect predecessor under the Mortgage to the Company (the Company being successor under the Mortgage to NorthWestern Energy, L.L.C. (hereinafter called “NorthWestern Energy”), formerly known as The Montana Power, L.L.C., a limited liability company of the State of Montana, and NorthWestern Energy being the successor under the Mortgage to The Montana Power Company, a corporation of the State of Montana (hereinafter called the “Company-Montana”)), to Guaranty Trust Company of New York and Arthur E. Burke, as Trustees, to secure the payment of bonds issued or to be issued under and in accordance with the provisions of the Mortgage, reference to which Mortgage is hereby made, this instrument (hereinafter called the “Twenty-sixth Supplemental Indenture”) being supplemental thereto;

WHEREAS, by the Mortgage, the Company-New Jersey covenanted that it would execute and deliver such supplemental indenture or indentures and such further instruments and do such further acts as might be necessary or proper to carry out more effectually the purposes of the Indenture and to make subject to the lien of the Indenture any property thereafter acquired, made or constructed and intended to be subject to the lien thereof; and

WHEREAS, the Company-New Jersey executed and delivered to the Trustees its First Supplemental Indenture, dated as of May 1, 1954 (hereinafter called the “First Supplemental Indenture”), and its Second Supplemental Indenture, dated as of April 1, 1959 (hereinafter called the “Second Supplemental Indenture”); and

WHEREAS, the Company-New Jersey was merged into the Company-Montana on November 30, 1961, and to evidence the succession of the Company-Montana to the Company-New Jersey for purposes of the bonds and the Indenture and the assumption by the Company-Montana of the covenants and conditions of the Company-New Jersey in the bonds and in the Indenture contained and to enable the Company-Montana to have and exercise the powers and rights of the Company-New Jersey under the Indenture in accordance with the terms thereof, the Company-Montana executed and delivered to the Trustees its Third Supplemental Indenture, dated as of November 30, 1961 (hereinafter called the “Third Supplemental Indenture”); and

WHEREAS, the Company-Montana executed and delivered to the Trustees its Fourth Supplemental Indenture, dated as of April 1, 1970 (hereinafter called the “Fourth Supplemental Indenture”); its Fifth Supplemental Indenture, dated as of April 1, 1971 (hereinafter called the “Fifth Supplemental Indenture”); its Sixth Supplemental Indenture, dated as of March 1, 1974 (hereinafter called the “Sixth Supplemental Indenture”); its Seventh Supplemental Indenture, dated as of December 1, 1974 (hereinafter called the “Seventh Supplemental Indenture”); its Eighth Supplemental Indenture, dated as of July 1, 1975 (hereinafter called the “Eighth Supplemental Indenture”); its Ninth Supplemental Indenture, dated as of December 1, 1975 (hereinafter called the “Ninth Supplemental Indenture”); its Tenth Supplemental Indenture, dated as of January 1, 1979 (hereinafter called the “Tenth Supplemental Indenture”); its Eleventh Supplemental Indenture, dated as of October 1, 1983 (hereinafter called the “Eleventh Supplemental Indenture”); its Twelfth Supplemental Indenture, dated as of January 1, 1984 (hereinafter called the “Twelfth Supplemental Indenture”); its Thirteenth Supplemental Indenture, dated as of December 1, 1991 (hereinafter called the “Thirteenth Supplemental Indenture”); its Fourteenth Supplemental Indenture, dated as of January 1, 1993 (hereinafter called the “Fourteenth Supplemental Indenture”); its Fifteenth Supplemental Indenture, dated as of March 1, 1993 (hereinafter called the “Fifteenth Supplemental Indenture”); its Sixteenth Supplemental Indenture, dated as of May 1, 1993 (hereinafter called the “Sixteenth Supplemental Indenture”); its Seventeenth Supplemental Indenture, dated as of December 1, 1993 (hereinafter called the “Seventeenth Supplemental Indenture”); its Eighteenth Supplemental Indenture, dated as of August 5, 1994 (hereinafter called the “Eighteenth Supplemental Indenture”); its Nineteenth Supplemental Indenture, dated as of December 16, 1999 (hereinafter called the “Nineteenth Supplemental Indenture”); and its Twentieth Supplemental Indenture, dated as of November 1, 2001 (hereinafter called the “Twentieth Supplemental Indenture”); and

WHEREAS, the Company-Montana was merged into NorthWestern Energy (under its then name, The Montana Power, L.L.C.) on February 13, 2002; and to evidence the succession of NorthWestern Energy (under its then name, The Montana Power, L.L.C.) to the Company-Montana for purposes of the bonds and the Indenture and the assumption by NorthWestern Energy (under its then name, The Montana Power, L.L.C.) of the covenants and conditions of the Company-Montana in the bonds and in the Indenture contained and to enable NorthWestern Energy (under its then name, The Montana Power, L.L.C.) to have and

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exercise the powers and rights of the Company-Montana under the Indenture in accordance with the terms thereof, NorthWestern Energy (under its then name, The Montana Power, L.L.C.) executed and delivered to the Trustees its Twenty-first Supplemental Indenture, dated as of February 13, 2002 (hereinafter called the “Twenty-first Supplemental Indenture”); and

WHEREAS, NorthWestern Energy changed its name from The Montana Power, L.L.C. to NorthWestern Energy, L.L.C. on March 19, 2002; and

WHEREAS, NorthWestern Energy transferred, subject to the Lien of the Indenture, substantially all of the Mortgaged and Pledged Property as an entirety to the Company on November 20, 2002 (the “Transfer Date”), and to evidence the succession of the Company to NorthWestern Energy for purposes of the bonds and the Indenture and the assumption by the Company of the covenants and conditions of NorthWestern Energy in the bonds and in the Indenture contained and to enable the Company to have and exercise the powers and rights of NorthWestern Energy under the Indenture in accordance with the terms thereof, the Company executed and delivered to the Trustees its Twenty-second Supplemental Indenture, dated as of November 15, 2002 (hereinafter called the “Twenty-second Supplemental Indenture”); and

WHEREAS, the Company executed and delivered to the Trustees its Twenty-third Supplemental Indenture, dated as of February 1, 2003 (hereinafter called the “Twenty-third Supplemental Indenture”); its Twenty-fourth Supplemental Indenture, dated as of November 1, 2004 (hereinafter called the “Twenty-fourth Supplemental Indenture”); and its Twenty-fifth Supplemental Indenture, dated as of April 1, 2006 (hereinafter called the “Twenty-fifth Supplemental Indenture”); and

WHEREAS, the Mortgage and the First, Second, Third, Fourth, Fifth, Sixth, Seventh, Eighth, Ninth, Tenth, Eleventh, Twelfth, Thirteenth, Fourteenth, Fifteenth, Sixteenth, Seventeenth, Eighteenth, Nineteenth, Twentieth, Twenty-first, Twenty-second, Twenty-third, Twenty-fourth and Twenty-fifth Supplemental Indentures were recorded in the official records of various counties and states as required by the Indenture; and

WHEREAS, the Company expects to record this Twenty-sixth Supplemental Indenture in the official records of various counties and states as required by the Indenture;

WHEREAS, an instrument dated March 15, 1955 was executed by the Company-New Jersey appointing Karl R. Henrich as Co-Trustee in succession to said Arthur E. Burke, resigned, under the Mortgage and by Karl R. Henrich accepting the appointment as Co-Trustee under the Mortgage in succession to said Arthur E. Burke, which instrument was recorded in various counties in the states of Montana, Idaho and Wyoming; and

WHEREAS, an instrument dated June 29, 1962 was executed by the Company-Montana appointing H.H. Gould as Co-Trustee in succession to said Karl R. Henrich, resigned, under the Mortgage and by H.H. Gould accepting the appointment as Co-Trustee

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under the Mortgage in succession to said Karl R. Henrich, which instrument was recorded in various counties in the states of Montana, Idaho and Wyoming; and

WHEREAS, an instrument dated June 22, 1973 was executed by the Company-Montana appointing R. Amundsen as Co-Trustee in succession to said H.H. Gould, resigned, under the Mortgage and by R. Amundsen accepting the appointment as Co-Trustee under the Mortgage in succession to said H.H. Gould, which instrument was recorded in various counties in the states of Montana, Idaho and Wyoming; and

WHEREAS, an instrument dated July 1, 1986 was executed by the Company-Montana appointing P.J. Crowley as Co-Trustee in succession to said R. Amundsen, resigned, under the Mortgage and by P.J Crowley accepting the appointment as Co-Trustee under the Mortgage in succession to said R. Amundsen, which instrument was recorded in various counties in the states of Montana, Idaho and Wyoming; and

WHEREAS, by the Eighteenth Supplemental Indenture, the Company-Montana appointed (i) W.T. Cunningham as Co-Trustee in succession to said P.J. Crowley, resigned, under the Mortgage and W.T. Cunningham accepted the appointment as Co-Trustee under the Mortgage in succession to said P.J. Crowley, and (ii) The Bank of New York as Corporate Trustee in succession to Morgan Guaranty Trust Company of New York, resigned, under the Mortgage and The Bank of New York accepted the appointment as Corporate Trustee under the Mortgage in succession to said Morgan Guaranty Trust Company of New York, which supplemental indenture was recorded in various counties in the states of Montana, Idaho and Wyoming; and

WHEREAS, an instrument dated March 29, 1999 was executed by the Company-Montana appointing Douglas J. MacInnes as Co-Trustee in succession to said W.T. Cunningham, resigned, under the Mortgage and by Douglas J. MacInnes accepting the appointment as Co-Trustee under the Mortgage in succession to said W.T. Cunningham, which instrument was recorded in various counties in the states of Montana, Idaho and Wyoming; and

WHEREAS, by the Twenty-third Supplemental Indenture, the Company appointed MaryBeth Lewicki as Co-Trustee in succession to said Douglas J. MacInnes, removed, under the Mortgage and MaryBeth Lewicki accepted the appointment as Co-Trustee under the Mortgage in succession to said Douglas J. MacInnes; and

WHEREAS, by the Twenty-fifth Supplemental Indenture, the Company appointed Ming Ryan as Co-Trustee in succession to said MaryBeth Lewicki, removed, under the Mortgage and Ming Ryan accepted the appointment as Co-Trustee under the Mortgage in succession to said Mary Beth Lewicki; and

WHEREAS, the Company-New Jersey, the Company-Montana or the Company has heretofore issued, in accordance with the provisions of the Mortgage, the following series of

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First Mortgage Bonds:

Series	Principal Amount Issued	Principal Amount Outstanding
2-7/8% Series due 1975	$40,000,000	NONE
3-1/8% Series due 1984	6,000,000	NONE
4-1/2% Series due 1989	15,000,000	NONE
8-1/4% Series due 1974	30,000,000	NONE
7-1/2% Series due 2001	25,000,000	NONE
8-5/8% Series due 2004	60,000,000	NONE
8-3/4% Series due 1981	30,000,000	NONE
9.60% Series due 2005	35,000,000	NONE
9.70% Series due 2005	65,000,000	NONE
9-7/8% Series due 2009	50,000,000	NONE
11-3/4% Series due 1993	75,000,000	NONE
10/10-1/8% Series due 2004/2014	80,000,000	NONE
8-1/8% Series due 2014	41,200,000	NONE
7.70% Series due 1999	55,000,000	NONE
8-1/4% Series due 2007 (Fifteenth)	55,000,000	$365,000
8.95% Series 2022	50,000,000	NONE
Secured Medium-Term Notes	68,000,000	NONE
7% Series due 2005	50,000,000	NONE
6-1/8% Series due 2023 (Nineteenth)	90,205,000	NONE
5.90% Series due 2023 (Twentieth)	80,000,000	NONE
0% Series due 1999	210,321,007	NONE
7.30% Series due 2006 (Twenty-second)	150,000,000	150,000,000
Collateral (2002) Series due 2006	280,000,000	NONE
Collateral (2004) Series A due 2009	90,000,000	NONE
Collateral (2004) Series B due 2011	72,000,000	NONE
Collateral (2004) Series C due 2014 (Twenty-sixth)	161,000,000	161,000,000
4.65% Series due 2023	170,205,000	170,205,000

which bonds are also hereinafter sometimes called “Bonds of the First through Twenty-seventh Series”, respectively; and

WHEREAS, Section 8 of the Mortgage provides that the form of each series of bonds (other than the First Series) issued thereunder and of the coupons to be attached to coupon bonds of such series shall be established by Resolution of the Board of Directors of the Company and that the form of such series, as established by said Board of Directors, shall

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specify the descriptive title of the bonds and various other terms thereof, and may also contain such provisions not inconsistent with the provisions of the Indenture as the Board of Directors may, in its discretion, cause to be inserted therein expressing or referring to the terms and conditions upon which such bonds are to be issued and/or secured under the Indenture; and

WHEREAS, Section 120 of the Mortgage provides, among other things, that any power, privilege or right expressly or impliedly reserved to or in any way conferred upon the Company by any provision of the Indenture, whether such power, privilege or right is in any way restricted or is unrestricted, may be in whole or in part waived or surrendered or subjected to any restriction if at the time unrestricted or to additional restriction if already restricted, and the Company may enter into any further covenants, limitations or restrictions for the benefit of any one or more series of bonds issued thereunder, or the Company may cure any ambiguity contained therein or in any supplemental indenture or may (in lieu of establishment by Resolution as provided in Section 8 of the Mortgage) establish the terms and provisions of any series of bonds other than the First Series, by an instrument in writing executed and acknowledged by the Company in such manner as would be necessary to entitle a conveyance of real estate to record in all of the states in which any property at the time subject to the lien of the Indenture shall be situated; and

WHEREAS, the Company now desires to create a new series of bonds (the “Bonds of the Twenty-eighth Series”, which term shall include the Private Bonds and the Exchange Bonds (each as defined herein), unless the context otherwise requires) and (pursuant to the provisions of Section 120 of the Mortgage) to add to its covenants and agreements contained in the Mortgage certain other covenants and agreements to be observed by it and to alter and amend in certain respects the covenants and provisions contained in the Indenture; and

WHEREAS, the Company and the initial purchasers of the Bonds of the Twenty-eighth Series are entering into a Registration Rights Agreement dated September 13, 2006 (the “Registration Rights Agreement”) which requires the Company to use commercially reasonable efforts to make a Registered Exchange Offer which would enable holders of the Bonds of the Twenty-eighth Series to exchange such bonds for Securities not subject to certain restrictions under the Securities Act or to cause a Shelf Registration Statement to become effective with respect to the Bonds of the Twenty-eighth Series (in each case as defined in such Registration Rights Agreement); and

WHEREAS, the execution and delivery by the Company of this Twenty-sixth Supplemental Indenture, and the terms of the Bonds of the Twenty-eighth Series, hereinafter referred to, have been duly authorized by the Board of Directors of the Company by appropriate Resolutions of said Board of Directors.

NOW, THEREFORE, THIS INDENTURE WITNESSETH:

That the Company, in consideration of the premises and of $1.00 to it duly paid by

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the Trustees at or before the ensealing and delivery of these presents, the receipt whereof is hereby acknowledged, and in further evidence of assurance of the estate, title and rights of the Trustees and in order further to secure the payment of both the principal of and interest and premium, if any, on the bonds from time to time issued under the Indenture, according to their tenor and effect and the performance of all the provisions of the Indenture (including any modification made as in the Mortgage provided) and of said bonds, and to confirm the lien of the Mortgage, as heretofore supplemented, on certain after-acquired property, hereby grants, bargains, sells, releases, conveys, assigns, transfers, mortgages, pledges, sets over and confirms (subject, however, to Excepted Encumbrances as defined in Section 6 of the Mortgage, as heretofore supplemented) unto Ming Ryan, Co-Trustee, and (to the extent of its legal capacity to hold the same for the purposes hereof) to The Bank of New York, the Corporate Trustee, as Trustees under the Indenture, and to their successor or successors in said trust, and to said Trustees and their successors and assigns forever, all property, real, personal and mixed, of the kind or nature specifically mentioned in the Mortgage, as heretofore supplemented, or of any other kind or nature (whether or not located in the State of Montana), acquired by the Company after the date of the execution and delivery of the Mortgage, as heretofore supplemented (except any herein or in the Mortgage, as heretofore supplemented, expressly excepted), now owned or, subject to the provisions of subsection (I) of Section 87 of the Mortgage, as heretofore supplemented, hereafter acquired by the Company (by purchase, consolidation, merger, donation, construction, erection or in any other way) and wheresoever situated, including (without in anywise limiting or impairing by the enumeration of the same the scope and intent of the foregoing, or of any general description contained in the Indenture) all lands, power sites, flowage rights, water rights, water locations, water appropriations, ditches, flumes, reservoirs, reservoir sites, canals, raceways, dams, dam sites, aqueducts and all other rights or means for appropriating, conveying, storing and supplying water; all rights of way and roads; all plants for the generation of electricity by steam, water and/or other power; all powerhouses, gas plants, street lighting systems, standards and other equipment incidental thereto, telephone, radio and television systems, air-conditioning systems and equipment incidental thereto, water works, water systems, steam heat and hot water plants, substations, lines, service and supply systems, bridges, culverts, tracks, ice or refrigeration plants and equipment, offices, buildings and other structures and the equipment thereof, all machinery, engines, boilers, dynamos, electric, gas and other machines, regulators, meters, transformers, generators, motors, electrical, gas and mechanical appliances, conduits, cables, water, steam heat, gas or other pipes, gas mains and pipes, service pipes, fittings, valves and connections, pole and transmission lines, wires, cables, tools, implements, apparatus, furniture and chattels; all franchises, consents or permits, all lines for the transmission and distribution of electric current, gas, steam heat or water for any purpose including towers, poles, wires, cables, pipes, conduits, ducts and all apparatus for use in connection therewith; all real estate, lands, easements, servitudes, licenses, permits, franchises, privileges, rights of way and other rights in or relating to real estate or the occupancy of the same and (except as herein or in the Mortgage, as heretofore supplemented, expressly excepted) all the right, title and interest of the Company in and to all other property of any kind or nature appertaining to and/or used and/or occupied and/or enjoyed in connection with any property hereinbefore or in the

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Mortgage, as heretofore supplemented, described.

TOGETHER with all and singular the tenements, hereditaments, prescriptions, servitudes and appurtenances belonging or in anywise appertaining to the aforesaid property or any part thereof, with the reversion and reversions, remainder and remainders and (subject to the provisions of Section 57 of the Mortgage) the tolls, rents, revenues, issues, earnings, income, product and profits thereof, and all the estate, right, title and interest and claim whatsoever, at law as well as in equity, which the Company now has or may hereafter acquire in and to the aforesaid property and franchises and every part and parcel thereof.

IT IS HEREBY AGREED by the Company that, subject to the provisions of subsection (I) of Section 87 of the Mortgage, as heretofore supplemented, all the property, rights and franchises acquired by the Company (by purchase, consolidation, merger, donation, construction, erection or in any other way) after the date hereof, except any herein or in the Mortgage, as heretofore supplemented, expressly excepted, shall be and are as fully granted and conveyed hereby and as fully embraced within the lien hereof and the lien of the Mortgage, as heretofore supplemented, as if such property, rights and franchises were now owned by the Company and were specifically described herein and conveyed hereby.

PROVIDED that the following are not and are not intended to be now or hereafter granted, bargained, sold, released, conveyed, assigned, transferred, mortgaged, hypothecated, affected, pledged, set over or confirmed hereunder and are hereby expressly excepted from the lien and operation of the Mortgage, as supplemented, viz:  (1) cash, shares of stock, bonds, notes and other obligations and other securities not specifically pledged, paid, deposited, delivered or held under the Mortgage, as supplemented, or covenanted so to be; (2) merchandise, equipment, apparatus, materials or supplies held for the purpose of sale or other disposition in the usual course of business; fuel, oil and similar materials and supplies consumable in the operation of any of the properties of the Company; all aircraft, tractors, rolling stock, trolley coaches, buses, motor coaches, automobiles, motor trucks, and other vehicles and materials and supplies held for the purpose of repairing or replacing (in whole or part) any of the same; (3) bills, notes and accounts receivable, judgments, demands and choses in action, and all contracts, leases and operating agreements not specifically pledged under the Mortgage, as supplemented, or covenanted so to be; the Company’s contractual rights or other interest in or with respect to tires not owned by the Company; (4) the last day of the term of any lease or leasehold which may be or become subject to the lien of the Mortgage, as supplemented; (5) electric energy, gas, steam, water, ice, and other materials or products generated, manufactured, produced, purchased or acquired by the Company for sale, distribution or use in the ordinary course of its business; all timber, minerals, mineral rights and royalties and all Gas and Oil Production Property, as defined in Section 4 of the Mortgage, as supplemented; (6) the Company’s franchise to be a corporation; and (7) any property heretofore released pursuant to any provisions of the Indenture and not heretofore disposed of by the Company-New Jersey, the Company-Montana, NorthWestern Energy or the Company; provided, however, that the property and rights expressly excepted from the lien and operation of the Mortgage, as supplemented, in the above subdivisions (2) and

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(3) shall (to the extent permitted by law) cease to be so excepted in the event and as of the date that either or both of the Trustees or a receiver or trustee shall enter upon and take possession of the Mortgaged and Pledged Property in the manner provided in Article XIII of the Mortgage by reason of the occurrence of a Default as defined in Section 65 thereof.

TO HAVE AND TO HOLD all such properties, real, personal and mixed, granted, bargained, sold, released, conveyed, assigned, transferred, mortgaged, pledged, set over or confirmed by the Company as aforesaid, or intended so to be, unto the Co-Trustee and (to the extent of its legal capacity to hold the same for the purposes hereto) unto the Corporate Trustee, as Trustees, and their successors and assigns forever.

IN TRUST NEVERTHELESS, for the same purposes and upon the same terms, trusts and conditions and subject to and with the same provisos and covenants as are set forth in the Mortgage, as supplemented, this Twenty-sixth Supplemental Indenture being supplemental thereto.

AND IT IS HEREBY COVENANTED by the Company that all the terms, conditions, provisos, covenants and provisions contained inthe Mortgage, as supplemented, shall affect and apply to the property hereinbefore described and conveyed and to the estate, rights, obligations and duties of the Company and the Trustees and the beneficiaries of the trust with respect to said property, and to the Trustees and their successors as Trustees of said property in the same manner and with the same effect as if the said property had been owned by the Company-New Jersey at the time of the execution of the Mortgage, and had been specifically and at length described in and conveyed to the Trustees, by the Mortgage as a part of the property therein stated to be conveyed.

SUBJECT NEVERTHELESS, to the limitation permitted by subsection (I) of Section 87 of the Mortgage, as supplemented, namely, that notwithstanding the foregoing, the Mortgage, as supplemented, shall not become or be or be required to become or be a lien upon any of the properties or franchises owned by the Company on the Transfer Date or thereafter acquired by the Company (by purchase, consolidation, merger, donation, construction, erection or in any other way) except (a) those acquired by it from NorthWestern Energy, and improvements, extensions and additions thereto and renewals and replacements thereof, (b) the property made and used by the Company as the basis under any of the provisions of the Indenture for the authentication and delivery of additional bonds or the withdrawal of cash or the release of property or a credit under Section 39 or Section 40 of the Indenture, and (c) such franchises, repairs and additional property as may be acquired, made or constructed by the Company (1) to maintain, renew and preserve the franchises covered by the Indenture, or (2) to maintain the property mortgaged and intended to be mortgaged under the Indenture as an operating system or systems in good repair, working order and condition, or (3) in rebuilding or renewal of property, subject to the Lien under the Indenture, damaged or destroyed, or (4) in replacement of or substitution for machinery, apparatus, equipment, frames, towers, poles, wire, pipe, tools, implements and furniture, subject to the Lien thereunder, which shall have become old, inadequate, obsolete, worn out, unfit, unadapted,

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unserviceable, undesirable or unnecessary for use in the operation of the property mortgaged and intended to be mortgaged thereunder.

The Company further covenants and agrees to and with the Trustees and their successors in said trust under the Indenture, as follows:

ARTICLE I

Twenty-eighth Series of Bonds

Section 1.01. General Terms of Bonds to be Issued.

(a)There is hereby created a series of bonds designated: “6.04% Series due 2016” (herein sometimes referred to as the Twenty-eighth Series; and the bonds of such Twenty-eighth Series are hereinafter referred to in this Article I as the “Bonds”), each of which shall bear the descriptive title “First Mortgage Bond.” Bonds of the Twenty-eighth Series shall mature on September 1, 2016 and shall be issued as fully registered bonds in minimum denominations of $1,000 and integral multiples thereof; they shall bear interest at the rate of 6.04% per annum payable in arrears, plus any Additional Interest as shall be payable pursuant to Section 6 of the Registration Rights Agreement, the first interest payment to be made on March 1, 2007 and shall be for the period from the date of first authentication of the Bonds to March 1, 2007, with subsequent interest payments payable semiannually on March 1 and September 1 of each year (each such payment date, an “Interest Payment Date”); the principal of and interest on each Bond to be payable at the office or agency of the Company in the Borough of Manhattan, The City of New York, in such coin or currency of the United States of America as at the time of payment is legal tender for public and private debts. For purposes of this Twenty-sixth Supplemental Indenture, the term “interest” shall be deemed to include the Additional Interest payable pursuant to Section 6 of the Registration Rights Agreement. The Bonds shall be dated as in Section 10 of the Mortgage provided.

The Bonds shall be issued substantially in the form of Exhibit A or Exhibit B hereto, as applicable, and as further provided in Article II of this Twenty-sixth Supplemental Indenture, and shall be deposited on behalf of the purchasers of the Bonds represented thereby with the Corporate Trustee as custodian for The Depository Trust Company (DTC) or such other depositary as may be subsequently designated (the “Depositary”), shall be registered in the name of the Depositary or a nominee of the Depositary and the aggregate principal amount of Bonds so issued may from time to time be increased or decreased by adjustments made on the records of the Corporate Trustee and the Depository or its nominee.

At the option of the registered owner, any Bonds, upon surrender thereof for cancellation at the office or agency of the Company in the Borough of Manhattan, The City of New York, shall be exchangeable for a like aggregate principal amount of bonds of the same series of other authorized denominations.

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The Bonds shall be transferable upon the surrender thereof for cancellation, together with a written instrument of transfer in form approved by the Registrar, duly executed by the registered owner or by his duly authorized attorney, at the office or agency of the Company in the Borough of Manhattan, The City of New York.

Upon any exchange or transfer of Bonds, the Company may make a charge therefor sufficient to reimburse it for any tax or taxes or other governmental charge, as provided in Section 12 of the Mortgage, but the Company hereby waives any right to make a charge in addition thereto for any exchange or transfer of Bonds.

(b)Upon the delivery of this Twenty-sixth Supplemental Indenture, Bonds of the Twenty-eighth Series in the aggregate principal amount of $150,000,000 are to be issued and delivered, pursuant to Article VI of the Mortgage, forthwith and will be Outstanding in addition to $365,000 aggregate principal amount of Bonds of the Fifteenth Series Outstanding, $150,000,000 aggregate principal amount of Bonds of the Twenty-second Series Outstanding, $161,000,000 aggregate principal amount of Bonds of the Twenty-sixth Series Outstanding and $170,205,000 aggregate principal amount of Bonds of the Twenty-seventh Series Outstanding at the date of delivery of this Twenty-sixth Supplemental Indenture.

Section 1.02. Redemption.

(a)The Bonds will not be subject to any mandatory redemption, sinking fund or other obligation of the Company to amortize, redeem or retire the Bonds prior to maturity and, in any case, the Bonds shall not be redeemable prior to maturity at the option of any holder of Bonds. Bonds of the Twenty-eighth Series shall be redeemable, however, at the option of the Company subject to the requirements of the Indenture in whole or in part at anytime and from time to time, prior to maturity, upon notice to the holders of such Bonds by first class mail, mailed not less than 30 days but not more than 60 days prior to the date on which such Bonds are fixed to be redeemed (such date fixed for redemption, the “Redemption Date”), in cash at a redemption price (the “Redemption Price”) equal to (i) the greater of: (A) one hundred per centum (100%) of the principal amount of Bonds to be redeemed then Outstanding, and (B) the sum of the present values of the remaining scheduled payments of principal and interest on such Bonds to be redeemed (not including any portion of such payments of interest accrued as of the Redemption Date) discounted to the Redemption Date on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months) at the Adjusted Treasury Rate (as hereinafter defined), plus 20 basis points, plus (ii) accrued and unpaid interest to the Redemption Date, as calculated by an Independent Investment Banker (as hereinafter defined); provided, however, that such Redemption Price and other terms shall be in accordance with a Resolution of the Company’s Board of Directors which Resolution shall be filed with the Corporate Trustee.

(b)In the event of any redemption of the Bonds, neither the Company nor the Corporate Trustee shall be required to (i) register the transfer of or exchange any Bonds

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during a period beginning at the opening of business 15 days before any selection for redemption of such Bonds and ending at the close of business on the earliest date on which the relevant notice of redemption is deemed to have been given to all holders of Bonds to be redeemed or (ii) register the transfer of or exchange any Bonds so selected for redemption, in whole or in part, except the unredeemed portion of any Bonds being redeemed in part. Unless the Company defaults in payment of the redemption price, on and after the Redemption Date interest will cease to accrue on the Bonds of this series or portions thereof called for redemption.

(c)If the Company elects to redeem the Bonds in part, the Corporate Trustee shall select a fair and appropriate manner in which to determine which of the Bonds Outstanding are to be redeemed; provided that such manner shall be pursuant to the requirements of the Indenture.

(d) For purposes of this Section 1.02:

“Adjusted Treasury Rate” means, with respect to any Redemption Date:

• the yield, under the heading which represents the average for the immediately preceding week, appearing in the most recently published statistical release designated “H.15(519)” or any successor publication which is published weekly by the Board of Governors of the Federal Reserve System and which establishes yields on actively traded United States Treasury securities adjusted to constant maturity under the caption “Treasury Constant Maturities” for the maturity corresponding to the Comparable Treasury Issue (as hereinafter defined) (if no maturity is within three months before or after the Remaining Life (as hereinafter defined), yields for the two published maturities most closely corresponding to the Comparable Treasury Issue will be determined and the Adjusted Treasury Rate will be interpolated or extrapolated from such yields on a straight line basis, rounding to the nearest month); or

• if such release (or any successor release) is not published during the week preceding the calculation date or does not contain such yields, the rate per annum equal to the semi-annual equivalent yield to maturity of the Comparable Treasury Issue, calculated using a price for the Comparable Treasury Issue (expressed as a percentage of its principal amount) equal to the Comparable Treasury Price (as hereinafter defined) for such Redemption Date.

The Adjusted Treasury Rate will be calculated on the third Business Day (as hereinafter defined) preceding the Redemption Date.

“Comparable Treasury Issue” the United States Treasury security selected by an

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Independent Investment Banker (as hereinafter defined) as having a maturity comparable to the remaining term of the Bonds to be redeemed that would be used, at the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of comparable maturity to the remaining term of such Bonds (the “Remaining Life”).

“Comparable Treasury Price” means (1) the average of five Reference Treasury Dealer Quotations (as hereinafter defined) for such Redemption Date, after excluding the highest and lowest Reference Treasury Dealer Quotations, or (2) if the Independent Investment Banker (as hereinafter defined) obtains fewer than five such Reference Treasury Dealer Quotations, the average of all such quotations.

“Independent Investment Banker” means Credit Suisse Securities (USA) LLC and its successors, or if that firm is unwilling or unable to serve as such, an independent investment and banking institution of national standing appointed by the Company.

“Reference Treasury Dealer” means:

• Credit Suisse Securities (USA) LLC and its successors; provided that, if Credit Suisse Securities (USA) LLC ceases to be a primary U.S. Government securities dealer in New York City (Primary Treasury Dealer), another Primary Treasury Dealer appointed by the Company; and

• up to four other Primary Treasury Dealers selected by the Company.

“Reference Treasury Dealer Quotations” means, with respect to each Reference Treasury Dealer and any Redemption Date, the average, as determined by the Independent Investment Banker, of the bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted in writing to the Independent Investment Banker at 5:00 p.m., New York City time, on the third Business Day preceding such Redemption Date.

The Corporate Trustee shall be under no duty to inquire into, may conclusively presume the correctness of, and shall be fully protected in acting upon the calculation by the Independent Investment Banker of any Redemption Price of the Bonds.

Section 1.03. Interest.

The Bonds shall bear interest for each Interest Period (as hereinafter defined) at a rate per annum of 6.04%, plus Additional Interest payable pursuant to Section 6 of the Registration Rights Agreement.

The period commencing on an Interest Payment Date and ending on the day preceding the next succeeding Interest Payment Date shall be an “Interest Period” provided that the first Interest Period shall begin on the date of the first authentication of the Bonds

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and extend through February 28, 2007, the day preceding the first Interest Payment Date.

Interest payments for the Bonds will be computed and paid on the basis of a 360-day year of twelve 30-day months. If an Interest Payment Date or Redemption Date falls on a day that is not a Business Day, such Interest Payment Date or Redemption Date, as the case may be, will be the immediately succeeding Business Day with the same force and effect as if made on the original Interest Payment Date or Redemption Date, as the case may be, and no interest shall accrue for the period from and after such original Interest Payment Date or Redemption Date, as the case may be. All dollar amounts resulting from such calculation will be rounded, if necessary, to the nearest cent with one-half cent rounded upward.

Interest on any Bond which is payable, and is punctually paid or duly provided for, on any Interest Payment Date shall be paid to the Person in whose name that Bond (or one or more Predecessor Bonds) is registered at the close of business on the Record Date for such interest; provided, however, that interest payable at maturity (whether the stated maturity or maturity resulting from declaration of acceleration, call for redemption or otherwise) shall be payable to the Person to whom the principal of such Bond shall be payable.

Section 1.04 Registration Rights and Exchange. The Company has entered into a Registration Rights Agreement dated September 13, 2006 (the “Registration Rights Agreement”) with the initial purchasers of the Bonds of the Twenty-eighth Series pursuant to which, among other things, the Bonds that are issued without registration (the “Private Bonds”) under the Securities Act of 1933, as amended (the “Securities Act’), may be exchanged for Bonds that will be registered under the Securities Act and that will otherwise have substantially the same terms as the Private Bonds (the “Exchange Bonds”) or, failing such exchange, the Company will file a shelf registration for the resale of the Private Bonds. The Private Bonds will be offered and sold in reliance on exemptions from, or in transactions not subject to, the Securities Act, and Private Bonds will be exchanged for Exchange Bonds only pursuant to an effective registration statement under the Securities Act and otherwise in accordance with the Registration Rights Agreement and the Mortgage. Except as provided in the Registration Rights Agreement, nothing in the Mortgage or the Bonds shall be construed to require the Company to register any Bonds under the Securities Act, or to make any transfer of such Bonds in violation of applicable law. The Private Bonds and the Exchange Bonds will constitute a single series of Bonds under the Mortgage.

ARTICLE II

Transfer and Exchange of Bonds; Book Entry.

Section 2.01. Form of Bonds.

(a)Private Bonds of the Twenty-eighth Series shall be substantially in the form of Exhibit A attached hereto. Exchange Bonds of the Twenty-eighth Series shall be substantially in the form of Exhibit B attached hereto. Each Bond shall represent such

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aggregate principal amount of the outstanding Bonds as shall be specified therein and each shall provide that it shall represent the aggregate principal amount of outstanding Bonds from time to time endorsed thereon and that the aggregate principal amount of outstanding Bonds represented thereby may from time to time be reduced or increased, as appropriate, to reflect exchanges and redemptions. Any endorsement of a Global Bond to reflect the amount of any increase or decrease in the aggregate principal amount of outstanding Bonds represented thereby shall be made by the Corporate Trustee, the Depositary or the Bond Custodian, at the direction of the Corporate Trustee, in accordance with instructions given by the Holder thereof as required by Section 2.03 of this Article.

(b)The provisions of the “Operating Procedures of the Euroclear System” and “Terms and Conditions Governing Use of Euroclear” and the “General Terms and Conditions of Clearstream Bank” and “Customer Handbook” of Clearstream shall be applicable to transfers of beneficial interests in the Regulation S Global Bonds that are held by members of, or Participants, in DTC through Euroclear or Clearstream.

(c)The Corporate Trustee has been appointed by the Depositary to act as Bond Custodian with respect to the Global Bonds.

Section 2.02.Transfer and Exchange of Global Bonds. A Global Bond may not be transferred as a whole except by the Depositary to a nominee of the Depositary, by a nominee of the Depositary to the Depositary or to another nominee of the Depositary, or by the Depositary or any such nominee to a successor Depositary or a nominee of such successor Depositary. All Global Bonds shall be exchanged by the Company for Certificated Bonds only if:

(a)the Company delivers to the Corporate Trustee notice from the Depositary that it is unwilling or unable to continue to act as Depositary for the Global Bonds or that it is no longer a clearing agency registered under the Exchange Act and, in either case, a successor Depositary is not appointed by the Company within 90 days after the date of such notice from the Depositary or

(b)the Company, at its option, notifies the Corporate Trustee in writing that it elects to cause issuance of the Bonds of the Twenty-eighth Series in certificated form, subject to the procedures of the Depositary; or

(c)there has occurred and is continuing a Default with respect to the Bonds of the Twenty-eighth Series.

Upon the occurrence of any of the preceding events in (a), (b) or (c) above, Certificated Bonds shall be issued in such names as the Depositary shall instruct the Corporate Trustee. Subject to the provisions of this Twenty-sixth Supplemental Indenture, Global Bonds also may be exchanged or replaced, in whole or in part, as

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provided in Sections 12 and 16 of the Indenture. Every Bond of the Twenty-eighth Series authenticated and delivered in exchange for, or in lieu of, a Global Bond or any portion thereof, pursuant to Sections 12 and 16 of the Indenture, shall be authenticated and delivered in the form of, and shall be, a Global Bond. A Global Bond may not be exchanged for another Bond of the Twenty-eighth Series other than as provided in this Section 2.02(c), however, beneficial interests in a Global Bond may be transferred and exchanged as provided in Sections 2.03, 2.04 or 2.07 of this Article.

Section 2.03.Transfer and Exchange of Beneficial Interests in the Global Bonds. The transfer and exchange of beneficial interests in the Global Bonds shall be effected through the Depositary, in accordance with the provisions of this Twenty-sixth Supplemental Indenture and the Applicable Procedures. Beneficial interests in the Restricted Global Bonds shall be subject to restrictions on transfer comparable to those set forth herein to the extent required by the Securities Act. Transfers of beneficial interests in the Global Bonds also shall require compliance with either subparagraph (a) or (b) below, as applicable, as well as one or more of the other following subparagraphs as applicable:

(a)Transfer of Beneficial Interests in the Same Global Bond. Beneficial interests in any Restricted Global Bond may be transferred to Persons who take delivery thereof in the form of a beneficial interest in the same Restricted Global Bond in accordance with the transfer restrictions set forth in the Private Placement Legend; provided, however, that prior to the expiration of the Restricted Period transfers of beneficial interests in the Regulation S Global Bond may not be made to a U.S. Person or for the account or benefit of a U.S. Person (other than an Initial Purchaser). Beneficial interests in any Unrestricted Global Bond may be transferred only to Persons who take delivery thereof in the form of a beneficial interest in an Unrestricted Global Bond. No written orders or instructions shall be required to be delivered to the Registrar to effect the transfers described in this Section 2.03(a).

(b)All Other Transfers and Exchanges of Beneficial Interests in Global Bonds. In connection with all transfers and exchanges of beneficial interests (other than a transfer of a beneficial interest in a Global Bond to a Person who takes delivery thereof in the form of a beneficial interest in the same Global Bond), the transferor of such beneficial interest must deliver to the Registrar either:

(i)both (A) a written order from a Participant or an Indirect Participant given to the Depositary in accordance with the Applicable Procedures directing the Depositary to credit or cause to be credited a beneficial interest in another Global Bond in an amount equal to the beneficial interest to be transferred or exchanged and (B) instructions given in accordance with the Applicable Procedures containing information regarding the Participant account to be credited with such increase or

(ii) both (A) a written order from a Participant or an Indirect Participant

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given to the Depositary in accordance with the Applicable Procedures directing the Depositary to cause to be issued a Certificated Bond in an amount equal to the beneficial interest to be transferred or exchanged and (B) instructions given by the Depositary to the Registrar containing information regarding the Person in whose name such Certificated Bond shall be registered to effect the transfer or exchange referred to in (A) above.

Upon an Exchange Offer by the Company in accordance with Section 2.07 of this Twenty-sixth Supplemental Indenture, the requirements of this Section 2.03(b) shall be deemed to have been satisfied upon receipt by the Registrar of the instructions contained in the Letter of Transmittal delivered by the Holder of such beneficial interests in the Restricted Global Bonds. Upon notification from the Registrar that all of the requirements for transfer or exchange of beneficial interests in Global Bonds contained in this Twenty-sixth Supplemental Indenture, the Bonds of the Twenty-eighth Series and otherwise applicable under the Securities Act have been satisfied, the Corporate Trustee shall adjust the principal amount of the relevant Global Bonds pursuant to Section 2.09 of this Twenty-sixth Supplemental Indenture.

(c)Transfer of Beneficial Interests to Another Restricted Global Bond. A beneficial interest in any Restricted Global Bond may be transferred to a Person who takes delivery thereof in the form of a beneficial interest in another Restricted Global Bond if the transfer complies with the requirements of clause (b) above and the Registrar receives the following:

(i)if the transferee shall take delivery in the form of a beneficial interest in the Rule 144A Global Bond, then the transferor must deliver a certificate in the form of Exhibit C hereto, including the certifications in Item (1) thereof; or

(ii)if the transferee shall take delivery in the form of a beneficial interest in the Regulation S Global Bond, then the transferor must deliver a certificate in the form of Exhibit C hereto, including the certifications in Item (2) thereof.

(d)Transfer and Exchange of Beneficial Interests in a Restricted Global Bond for Beneficial Interests in the Unrestricted Global Bond. A beneficial interest in any Restricted Global Bond may be exchanged by any holder thereof for a beneficial interest in an Unrestricted Global Bond or transferred to a Person who takes delivery thereof in the form of a beneficial interest in an Unrestricted Global Bond if the exchange or transfer complies with the requirements of clause (b) above and:

(i)such exchange or transfer is effected pursuant to an Exchange Offer in accordance with the Registration Rights Agreement and the holder of the beneficial interest to be transferred, in the case of an exchange, or the transferee, in the case of a transfer, is not (A) a Broker-Dealer, (B) a Person participating in the distribution of the Exchange Securities

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or (C) a Person who is an affiliate (as defined in Rule 144) of the Company;

(ii)any such transfer is effected pursuant to a Shelf Registration Statement in accordance with the Registration Rights Agreement;

(iii)any such transfer is effected by a Broker-Dealer pursuant to an Exchange Offer Registration Statement in accordance with the Registration Rights Agreement; or

(iv) the Registrar receives the following:

(A)if the holder of such beneficial interest in a Restricted Global Bond proposes to exchange such beneficial interest for a beneficial interest in an Unrestricted Global Bond, a certificate from such holder in the form of Exhibit D hereto, including the certifications in Item (1)(a) thereof; or

(B)if the holder of such beneficial interest in a Restricted Global Bond proposes to transfer such beneficial interest to a Person who shall take delivery thereof in the form of a beneficial interest in an Unrestricted Global Bond, a certificate from such holder in the form of Exhibit C hereto, including the certifications in Item (4) thereof;

and, in each such case set forth in this subparagraph (iv), an Opinion of Counsel in form reasonably acceptable to the Company to the effect that such exchange or transfer is in compliance with the Securities Act and that the restrictions on transfer contained herein and in the Private Placement Legend are not required in order to maintain compliance with the Securities Act.

If any such transfer is effected pursuant to subparagraph (ii) or (iv) above at a time when an Unrestricted Global Bond has not yet been issued, the Company shall issue and, upon receipt of an authentication order in accordance with Article II of the Indenture, the Corporate Trustee shall authenticate one or more Unrestricted Global Bonds in an aggregate principal amount equal to the principal amount of beneficial interests transferred pursuant to subparagraph (ii) or (iv) above.

Beneficial interests in an Unrestricted Global Bond cannot be exchanged for, or transferred to Persons who take delivery thereof in the form of, a beneficial interest in a Restricted Global Bond.

Section 2.04 Transfer of Beneficial Interests for Certificated Bonds.

(a)Beneficial Interests in Restricted Global Bonds to Restricted Certificated Bonds. If any holder of a beneficial interest in a Restricted Global Bond proposes to transfer

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such beneficial interest to a Person who takes delivery thereof in the form of a Certificated Bond, then, upon receipt by the Registrar of the following documentation:

(i)if such beneficial interest is being transferred to a QIB in accordance with Rule 144A under the Securities Act, a certificate to the effect set forth in Exhibit C hereto, including the certifications in Item (1) thereof;

(ii)if such beneficial interest is being transferred to a Non-U.S. Person in an offshore transaction in accordance with Rule 903 or Rule 904 under the Securities Act, a certificate to the effect set forth in Exhibit C hereto, including the certifications in Item (2) thereof;

(iii)if such beneficial interest is being transferred pursuant to an exemption from the registration requirements of the Securities Act in accordance with Rule 144 under the Securities Act, a certificate to the effect set forth in Exhibit C hereto, including the certifications in Item (3)(a) thereof;

(iv)if such beneficial interest is being transferred to an Institutional Accredited Investor or in reliance on any other exemption from the registration requirements of the Securities Act, in either case other than those listed in subparagraphs (i) through (iii) above, then the transferor must deliver a certificate in the form of Exhibit C hereto, including the certifications, certificates and any Opinion of Counsel required by Item (3) thereof, if applicable;

(v)if such beneficial interest is being transferred to the Company or any of its Subsidiaries, a certificate to the effect set forth in Exhibit C hereto, including the certifications in Item (3)(b) thereof; or

(vi)if such beneficial interest is being transferred pursuant to an effective registration statement under the Securities Act, a certificate to the effect set forth in Exhibit C hereto, including the certifications in Item (3)(c) thereof,

the Corporate Trustee, upon notice of receipt of such documentation by the Registrar, shall cause the aggregate principal amount of the applicable Global Bond to be reduced accordingly pursuant to Section 2.09 of this Article, and the Company shall execute and the Corporate Trustee shall authenticate and make available for delivery to the Person designated in the instructions a Certificated Bond in the appropriate principal amount. Any Certificated Bond issued to a Person who takes delivery thereof in the form of a Certificated Bond pursuant to this Section 2.04 shall be registered in such name or names and in such authorized denomination or denominations as the holder of such beneficial interest shall instruct the Registrar through instructions from the Depositary and the Participant or Indirect Participant. The Corporate Trustee shall make available for delivery such Certificated Bonds to the Persons in whose names such Bonds of the Twenty-eighth Series are so registered.

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Any Certificated Bond issued to a Person who takes delivery thereof in the form of a Certificated Bond pursuant to this Section 2.04 shall bear the Private Placement Legend and shall be subject to all restrictions on transfer contained therein.

Notwithstanding Sections 2.02 and 2.04 (a)(ii) hereof, a beneficial interest in the Regulation S Global Bond may not be (a) exchanged for a Certificated Bond prior to (x) the expiration of the Restricted Period and (y) the receipt by the Registrar of any certificates required pursuant to Rule 903(c)(3)(B) under the Securities Act or (b) transferred to a Person who takes delivery thereof in the form of a Certificated Bond prior to the conditions set forth in clause (a) above or unless the transfer is pursuant to an exemption from the registration requirements of the Securities Act other than Rule 903 or Rule 904.

(b)Beneficial Interests in Restricted Global Bonds to Unrestricted Certificated Bonds. Notwithstanding Section 2.04(a) hereof, a holder of a beneficial interest in a Restricted Global Bond may transfer such beneficial interest to a Person who takes delivery thereof in the form of an Unrestricted Certificated Bond only if:

(i)such transfer is effected pursuant to an Exchange Offer in accordance with the Registration Rights Agreement and the transferee is not (A) a broker-dealer, (B) a Person participating in the distribution of the Exchange Securities or (C) a Person who is an affiliate (as defined in Rule 144) of the Company;

(ii)any such transfer is effected pursuant to a Shelf Registration Statement in accordance with the Registration Rights Agreement;

(iii)any such transfer is effected by a Broker-Dealer pursuant to an Exchange Offer Registration Statement in accordance with the Registration Rights Agreement; or

(iv)if the holder of such beneficial interest in a Restricted Global Bond proposes to transfer such beneficial interest to a Person who shall take delivery thereof in the form of a Certificated Bond that does not bear the Private Placement Legend, the Registrar receives a certificate from such holder in the form of Exhibit C hereto, including the certifications in Item (4) thereof; and an Opinion of Counsel in form reasonably acceptable to the Company, to the effect that such transfer is in compliance with the Securities Act and that the restrictions on transfer contained herein and in the Private Placement Legend are not required in order to maintain compliance with the Securities Act.

(c)Beneficial Interests in Unrestricted Global Bonds to Unrestricted Certificated Bonds. If any holder of a beneficial interest in an Unrestricted Global Bond proposes to transfer such beneficial interest to a Person who takes delivery thereof in the form of a Certificated Bond, then, upon notice by the Registrar of satisfaction of the conditions set forth in Section 2.03(b) of this Article, the Corporate Trustee shall cause the aggregate

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principal amount of the applicable Global Bond to be reduced accordingly pursuant to Section 2.09 of this Article, and the Company shall execute and the Corporate Trustee shall authenticate and make available for delivery to the Person designated in the instructions a Certificated Bond in the appropriate principal amount. Any Certificated Bond issued to a Person who shall take delivery thereof in the form of a Certificated Bond pursuant to this Section 2.04(c) shall be registered in such name or names and in such authorized denomination or denominations as the holder of such beneficial interest shall instruct the Registrar through instructions from the Depositary and the Participant or Indirect Participant. The Corporate Trustee shall make available for delivery such Certificated Bonds to the Persons in whose names such Bonds of the Twenty-eighth Series are so registered. Any Certificated Bond issued to a Person who shall take delivery thereof in the form of a Certificated Bond pursuant to this Section 2.04(c) shall not bear the Private Placement Legend. A beneficial interest in an Unrestricted Global Bond cannot be transferred to a Person who takes delivery thereof in the form of a Certificated Bond bearing the Private Placement Legend.

Section 2.05. Transfer and Exchange of Certificated Bonds for Beneficial Interests.

(a)Restricted Certificated Bonds to Beneficial Interests in Restricted Global Bonds. If any Holder of a Restricted Certificated Bond proposes to exchange such Bonds of the Twenty-eighth Series for a beneficial interest in a Restricted Global Bond or to transfer such Certificated Bonds to a Person who takes delivery thereof in the form of a beneficial interest in a Restricted Global Bond, then, upon receipt by the Registrar of the following documentation:

(i)if the Holder of such Restricted Certificated Bond proposes to exchange such Bonds of the Twenty-eighth Series for a beneficial interest in a Restricted Global Bond, a certificate from such Holder in the form of Exhibit D hereto, including the certifications in Item (2)(b) thereof;

(ii)if such Certificated Bond is being transferred to a QIB in accordance with Rule 144A under the Securities Act, a certificate to the effect set forth in Exhibit C hereto, including the certifications in Item (1) thereof;

(iii)if such Certificated Bond is being transferred to a Non-U.S. Person in an offshore transaction in accordance with Rule 903 or Rule 904 under the Securities Act, a certificate to the effect set forth in Exhibit C hereto, including the certifications in Item (2) thereof;

(iv)if such Certificated Bond is being transferred pursuant to an exemption from the registration requirements of the Securities Act in accordance with Rule 144 under the Securities Act, a certificate to the effect set forth in Exhibit C hereto, including the certifications in Item (3)(a) thereof;

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(v)if such Certificated Bond is being transferred to an Institutional Accredited Investor or in reliance on any other exemption from the registration requirements of the Securities Act, in either case, other than those listed in subparagraphs (ii) through (iv) above, a certificate in the form of Exhibit C hereto, including certifications, certificates, and any Opinion of Counsel required by Item (3) thereof, if applicable;

(vi)if such Certificated Bond is being transferred to the Company or any of its Subsidiaries, a certificate to the effect set forth in Exhibit C hereto, including the certifications in Item (3)(b) thereof; or

(vii)if such Certificated Bond is being transferred pursuant to an effective registration statement under the Securities Act, a certificate to the effect set forth in Exhibit C hereto, including the certifications in Item (3)(c) thereof,

the Corporate Trustee, upon notice of receipt of such documentation by the Registrar, shall cancel the Certificated Bond, increase or cause to be increased the aggregate principal amount of, in the case of subparagraph (i) above, the appropriate Restricted Global Bond and, in the case of subparagraph (ii) above, the Rule 144A Global Bond, and, in the case of subparagraph (iii) above, the Regulation S Global Bond.

(b)Restricted Certificated Bonds to Beneficial Interests in Unrestricted Global Bonds. A Holder of a Restricted Certificated Bond may exchange such Bond of the Twenty-eighth Series for a beneficial interest in an Unrestricted Global Bond or transfer such Restricted Certificated Bond to a Person who takes delivery thereof in the form of a beneficial interest in an Unrestricted Global Bond only if:

(i)such exchange or transfer is effected pursuant to an Exchange Offer in accordance with the Registration Rights Agreement and the Holder, in the case of an exchange, or the transferee, in the case of a transfer, is not (A) a broker-dealer, (B) a Person participating in the distribution of the Exchange Securities or (C) a Person who is an affiliate (as defined in Rule 144) of the Company;

(ii)any such transfer is effected pursuant to a Shelf Registration Statement in accordance with the Registration Rights Agreement;

(iii)any such transfer is effected by a Broker-Dealer pursuant to an Exchange Offer Registration Statement in accordance with the Registration Rights Agreement; or

(iv)	the Registrar receives the following:
	(A)	if the Holder of such Certificated Bonds proposes to exchange

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such Bonds of the Twenty-eighth Series for a beneficial interest in the Unrestricted Global Bond, a certificate from such Holder in the form of Exhibit D hereto, including the certifications in Item (1)(c) thereof; or

(B)if the Holder of such Certificated Bonds proposes to transfer such Bonds of the Twenty-eighth Series to a Person who shall take delivery thereof in the form of a beneficial interest in the Unrestricted Global Bond, a certificate from such Holder in the form of Exhibit C hereto, including the certifications in Item (4) thereof;

and, in each such case set forth in this subparagraph (iv), an Opinion of Counsel in form reasonably acceptable to the Company to the effect that such exchange or transfer is in compliance with the Securities Act, that the restrictions on transfer contained herein and in the Private Placement Legend are not required in order to maintain compliance with the Securities Act, and such Certificated Bonds are being exchanged or transferred in compliance with any applicable blue sky securities laws of any State of the United States.

Upon satisfaction of the conditions of any of the subparagraphs in this Section 2.05(b), the Corporate Trustee shall cancel the Certificated Bonds and increase or cause to be increased the aggregate principal amount of the Unrestricted Global Bond.

(c)Unrestricted Certificated Bonds to Beneficial Interests in Unrestricted Global Bonds. A Holder of an Unrestricted Certificated Bond may exchange such Bond of the Twenty-eighth Series for a beneficial interest in an Unrestricted Global Bond or transfer such Certificated Bonds to a Person who takes delivery thereof in the form of a beneficial interest in an Unrestricted Global Bond at any time. Upon receipt of a request for such an exchange or transfer, the Corporate Trustee shall cancel the applicable Unrestricted Certificated Bond and increase or cause to be increased the aggregate principal amount of one of the Unrestricted Global Bonds.

If any such exchange or transfer from a Certificated Bond to a beneficial interest is effected pursuant to Sections 2.05(b)(ii) or (iv) of this Article or the first paragraph of this Section 2.05(c) at a time when an Unrestricted Global Bond has not yet been issued, the Company shall issue and, upon receipt of an authentication order in accordance with Article II of the Indenture, the Corporate Trustee shall authenticate one or more Unrestricted Global Bonds in an aggregate principal amount equal to the principal amount of beneficial interests transferred pursuant to Sections 2.05(b)(ii) or (iv) of this Article or the first paragraph of this Section 2.05(c).

Section 2.06.Transfer and Exchange of Certificated Bonds for Certificated Bonds. Upon request by a Holder of Certificated Bonds and such Holder’s compliance with the provisions of this Section 2.06, the Registrar shall register the transfer or exchange of

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Certificated Bonds. Prior to such registration of transfer or exchange, the requesting Holder shall present or surrender to the Registrar the Certificated Bonds duly endorsed or accompanied by a written instruction of transfer in form satisfactory to the Registrar duly executed by such Holder or by his attorney, duly authorized in writing. In addition, the requesting Holder shall provide any additional certifications, documents and information, as applicable, pursuant to the provisions of this 2.06(5).

(a)Restricted Certificated Bonds to Restricted Certificated Bonds. Restricted Certificated Bonds may be transferred to and registered in the name of Persons who take delivery thereof if the Registrar receives the following:

(i)if the transfer shall be made pursuant to Rule 144A under the Securities Act, then the transferor must deliver a certificate in the form of Exhibit C hereto, including the certifications in Item (1) thereof;

(ii)if the transfer shall be made pursuant to Rule 903 or Rule 904 of the Securities Act, then the transferor must deliver a certificate in the form of Exhibit C hereto, including the certifications in Item (2) thereof; and

(iii)if the transfer shall be made pursuant to any other exemption from the registration requirements of the Securities Act, then the transferor must deliver a certificate in the form of Exhibit C hereto, including the certifications, certificates and Opinion of Counsel required by Item (3) thereof, if applicable.

(b)Restricted Certificated Bonds to Unrestricted Certificated Bonds. Any Restricted Certificated Bond may be exchanged by the Holder thereof for an Unrestricted Certificated Bond or transferred to a Person or Persons who take delivery thereof in the form of an Unrestricted Certificated Bond if:

(i)such exchange or transfer is effected pursuant to an Exchange Offer in accordance with the Registration Rights Agreement and the Holder of such Bonds of the Twenty-eighth Series, in the case of an exchange, or the transferee, in the case of a transfer, is not (A) a broker-dealer, (B) a Person participating in the distribution of the Exchange Securities or (C) a Person who is an affiliate (as defined in Rule 144) of the Company;

(ii)any such transfer is effected pursuant to a Shelf Registration Statement in accordance with the Registration Rights Agreement;

(iii)any such transfer is effected by a Broker-Dealer pursuant to an Exchange Offer Registration Statement in accordance with the Registration Rights Agreement; or

(iv) the Registrar receives the following:

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(A)if the Holder of such Restricted Certificated Bonds proposes to exchange such Bonds of the Twenty-eighth Series for an Unrestricted Certificated Bond, a certificate from such Holder in the form of Exhibit D hereto, including the certifications in Item (1)(b) thereof; or

(B)if the Holder of such Restricted Certificated Bonds proposes to transfer such Bonds of the Twenty-eighth Series to a Person who shall take delivery thereof in the form of an Unrestricted Certificated Bond, a certificate from such Holder in the form of Exhibit C hereto, including the certifications in Item (4) thereof;

and, in each such case set forth in this subparagraph (iv), an Opinion of Counsel in form reasonably acceptable to the Company to the effect that such exchange or transfer is in compliance with the Securities Act, that the restrictions on transfer contained herein and in the Private Placement Legend are not required in order to maintain compliance with the Securities Act, and such Restricted Certificated Bond is being exchanged or transferred in compliance with any applicable blue sky securities laws of any State of the United States.

(c)Unrestricted Certificated Bonds to Unrestricted Certificated Bonds. A Holder of Unrestricted Certificated Bonds may transfer such Bonds of the Twenty-eighth Series to a Person who takes delivery thereof in the form of an Unrestricted Certificated Bond. Upon receipt of a request for such a transfer, the Registrar shall register the Unrestricted Certificated Bonds pursuant to the instructions from the Holder thereof. Unrestricted Certificated Bonds cannot be exchanged for or transferred to Persons who take delivery thereof in the form of a Restricted Certificated Bond.

Section 2.07.Exchange Offer. The Company shall inform the Corporate Trustee of the effective date of any registration statement registering the Exchange Bonds or the Private Bonds under the Securities Act. Upon the receipt of a request in writing from the Company and such other documents as reasonably requested by the Trustee from the Company, the Trustee will take such actions as shall be necessary to effectuate the exchange of any of the Private Bonds for Exchange Bonds, including but not limited to the issuance of Exchange Bonds in the form required by this Twenty-sixth Supplemental Indenture, the entry of decreases in the Regulation S Global Bond and the 144A Global Bond or, if applicable, the cancellation of Certificated Bonds.

Section 2.08.Legends. The following legends shall appear on the face of all Global Bonds and Certificated Bonds issued under this Twenty-Sixth Supplemental Indenture unless specifically stated otherwise in the applicable provisions of this Twenty-sixth Supplemental Indenture.

(a) Private Placement Legend.

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(i)Except as permitted by subparagraph (ii) below, each Bond that is a Private Bond (and all Bonds of the Twenty-eighth Series issued in exchange therefore or substitution thereof) shall bear the legend in substantially the following form:

“THIS BOND (OR ITS PREDECESSOR) WAS ORIGINALLY ISSUED IN A TRANSACTION EXEMPT FROM REGISTRATION UNDER THE UNITED STATES SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND THIS BOND MAY NOT BE OFFERED, SOLD OR OTHERWISE TRANSFERRED IN THE ABSENCE OF SUCH REGISTRATION OR AN APPLICABLE EXEMPTION THEREFROM. EACH PURCHASER OF THIS BOND IS HEREBY NOTIFIED THAT THE SELLER OF THIS BOND MAY BE RELYING ON THE EXEMPTION FROM THE PROVISIONS OF SECTION 5 OF THE SECURITIES ACT PROVIDED BY RULE 144A THEREUNDER.

THE HOLDER OF THIS BOND AGREES FOR THE BENEFIT OF THE COMPANY THAT (A) THIS BOND MAY BE OFFERED, RESOLD, PLEDGED OR OTHERWISE TRANSFERRED, ONLY (I) IN THE UNITED STATES TO A PERSON WHOM THE SELLER REASONABLY BELIEVES IS A QUALIFIED INSTITUTIONAL BUYER (AS DEFINED IN RULE 144A UNDER THE SECURITIES ACT) IN A TRANSACTION MEETING THE REQUIREMENTS OF RULE 144A, (II) OUTSIDE THE UNITED STATES IN AN OFFSHORE TRANSACTION IN ACCORDANCE WITH RULE 904 UNDER THE SECURITIES ACT, (III) PURSUANT TO AN EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT PROVIDED BY RULE 144A THEREUNDER (IF AVAILABLE), (IV) TO AN INSTITUTIONAL “ACCREDITED INVESTOR” (AS DEFINED IN RULE 501(a)(1), (2), (3) or (7) OF REGULATION D UNDER THE SECURITIES ACT) THAT, PRIOR TO SUCH TRANSFER, FURNISHES TO THE CORPORATE TRUSTEE A SIGNED LETTER CONTAINING CERTAIN REPRESENTATIONS AND AGREEMENTS RELATING TO THE TRANSFER OF THIS BOND (THE FORM OF WHICH CAN BE OBTAINED FROM THE CORPORATE TRUSTEE) AND, IF SUCH TRANSFER IS IN RESPECT OF AN AGGREGATE PRINCIPAL AMOUNT OF BONDS LESS THAN $250,000, AN OPINION OF COUNSEL ACCEPTABLE TO THE COMPANY THAT SUCH TRANSFER IS IN COMPLIANCE WITH THE SECURITIES ACT, OR (V) PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT, IN EACH OF CASES (I) THROUGH (V) IN ACCORDANCE WITH ANY APPLICABLE SECURITIES LAWS OF ANY STATE OF THE UNITED STATES, AND (B) THE HOLDER WILL, AND EACH SUBSEQUENT HOLDER IS REQUIRED TO, NOTIFY ANY PURCHASER OF THIS BOND FROM IT OF THE RESALE RESTRICTIONS REFERRED TO IN (A) ABOVE.”

(ii) Notwithstanding the foregoing, any Global Bond or Certificated Bond

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that is an Exchange Bond issued pursuant to Sections 2.03(d), 2.04(b), 2.05(b), 2.05(c), 2.06(b), 2.06(c) or 2.07 of this Article II (and all Bonds of the Twenty-eighth Series issued in exchange therefore or substitution thereof) shall not bear the Private Placement Legend.

(b)Global Bond Legend. Each Global Bond shall bear a legend in substantially the following form:

“THIS GLOBAL BOND IS HELD BY THE DEPOSITARY (AS DEFINED IN THE TWENTY-SIXTH SUPPLEMENTAL INDENTURE GOVERNING THIS BOND) OR ITS NOMINEE IN CUSTODY FOR THE BENEFIT OF THE BENEFICIAL OWNERS HEREOF, AND IS NOT TRANSFERABLE TO ANY PERSON UNDER ANY CIRCUMSTANCES EXCEPT THAT (I) THE CORPORATE TRUSTEE MAY MAKE SUCH NOTATIONS HEREON AS MAY BE REQUIRED PURSUANT TO ARTICLE II OF THE TWENTY-SIXTH SUPPLEMENTAL INDENTURE, (II) THIS GLOBAL BOND MAY BE EXCHANGED IN WHOLE BUT NOT IN PART PURSUANT TO SECTION 2.02 OF ARTICLE II OF THE TWENTY-SIXTH SUPPLEMENTAL INDENTURE, (III) THIS GLOBAL BOND MAY BE DELIVERED TO THE CORPORATE TRUSTEE FOR CANCELLATION PURSUANT TO ARTICLE II OF THE INDENTURE AND (IV) THIS GLOBAL BOND MAY BE TRANSFERRED TO A SUCCESSOR DEPOSITARY WITH THE PRIOR WRITTEN CONSENT OF THE COMPANY OR ANY SUCCESSOR THERETO.”

Additionally, for so long as DTC is the Depositary with respect to any Global Bond, each such Global Bond shall also bear a legend in substantially the following form:

“UNLESS THIS BOND IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITARY, TO THE COMPANY OR ANY SUCCESSOR THERETO OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE, OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITARY (AND ANY PAYMENT IS MADE TO CEDE & CO. OR TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITARY), ANY TRANSFER, PLEDGE, OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.”

(c)Regulation S Global Bond Legend.Each Regulation S Global Bond shall bear a legend in substantially the following form:

“THE RIGHTS ATTACHING TO THIS REGULATION S GLOBAL

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BOND, AND THE CONDITIONS AND PROCEDURES GOVERNING ITS EXCHANGE FOR CERTIFICATED BONDS, ARE AS SPECIFIED IN THE INDENTURE (AS DEFINED HEREIN AND AS HERETOFORE AMENDED AND SUPPLEMENTED). NEITHER THE HOLDER NOR THE BENEFICIAL OWNERS OF THIS REGULATION S GLOBAL BOND SHALL BE ENTITLED TO RECEIVE PAYMENT OF INTEREST HEREON. THIS PARAGRAPH SHALL BE APPLICABLE ONLY DURING THE DISTRIBUTION COMPLIANCE PERIOD (AS DEFINED IN THE TWENTY-SIXTH SUPPLEMENTAL INDENTURE).”

Section 2.09.Cancellation and/or Adjustment of Global Bonds. At such time as all beneficial interests in a particular Global Bond have been exchanged for Certificated Bonds or a particular Global Bond has been redeemed, repurchased or canceled in whole and not in part, each such Global Bond shall be returned to or retained and canceled by the Corporate Trustee in accordance with Section 13 of the Indenture. At any time prior to such cancellation, if any beneficial interest in a Global Bond is exchanged for or transferred to a Person who shall take delivery thereof in the form of a beneficial interest in another Global Bond or for Certificated Bonds, the principal amount of Bonds of the Twenty-eighth Series represented by such Global Bond shall be reduced accordingly and an endorsement shall be made on such Global Bond, by the Corporate Trustee, the Bond Custodian or the Depositary at the direction of the Corporate Trustee, to reflect such reduction; and if the beneficial interest is being exchanged for or transferred to a Person who shall take delivery thereof in the form of a beneficial interest in another Global Bond, such other Global Bond shall be increased accordingly and an endorsement shall be made on such Global Bond, by the Corporate Trustee, the Bond Custodian or by the Depositary at the direction of the Corporate Trustee, to reflect such increase.

Section 2.10. General Provisions Relating to Transfers and Exchanges.

(a)To permit registrations of transfers and exchanges, subject to this Article II, the Company shall execute and, upon the Company’s order, the Corporate Trustee or an Authenticating Agent shall authenticate Global Bonds and Certificated Bonds at the Registrar’s request. The Corporate Trustee has been appointed as Registrar with respect to the Bonds.

(b)All certifications, certificates and Opinions of Counsel required to be submitted to the Registrar pursuant to this Article II to effect a transfer or exchange may be submitted by facsimile.

(c)The Corporate Trustee and the Registrar shall have no obligation or duty to monitor, determine or inquire as to whether any Person is or is not a Person described in clauses (A), (B) and (C) of each of Sections 2.03(d)(i), 2.04(b)(i), 2.05(b)(i), 2.06(b)(i) and 2.07 of this Article or under applicable law with respect to any transfer of any interest in any

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Bond of the Twenty-eighth Series (including any transfers between or among Participants or beneficial owners of interests in any Global Bond) other than to require delivery of such certificates and other documentation or evidence as are expressly required by, and to do so if and when expressly required by the terms of, this Indenture, and to examine the same to determine substantial compliance as to form with the express requirements hereof.

ARTICLE III

Definitions

Section 3.01. Definitions.

The following terms shall have the meanings provided herein for all purposes of this Supplemental Indenture, unless the context clearly requires otherwise (such meanings to be equally applicable to both the singular and plural forms of the terms defined):

“144A Global Bond” means the global Bond in the form of Exhibit A hereto bearing the Global Bond Legend and the Private Placement Legend and deposited with, or in custody for, and registered in the name of the Depositary or its nominee that will be issued in a denomination equal to the outstanding principal amount of the Bonds sold in reliance on Rule 144A.

“Additional Interest” has the meaning set forth in Section 6 of the Registration Rights Agreement.

“Agent” means any Registrar, paying agent or co-registrar.

“Applicable Procedures” means, with respect to any transfer or exchange of or for beneficial interests in any Global Bond, the rules and procedures of the Depositary, Euroclear and Clearstream that apply to such transfer or exchange.

“Beneficial Owner” has the meaning assigned to such term in Rule 13d-3 and Rule 13d-5 under the Exchange Act, except that in calculating the beneficial ownership of any particular) person (as that term is used in Section 13(d)(3) of the Exchange Act), that “person” shall be deemed to have beneficial ownership of all securities that the “person” has the right to acquire by conversion or exercise of other securities, whether the right is currently exercisable or is exercisable only upon the occurrence of a subsequent condition. The terms “Beneficially Owns” and “Beneficially Owned” shall have a corresponding meaning.

“Business Day” means any day other than a Saturday, a Sunday or a legal holiday or a day on which banking institutions or trust companies are authorized or obligated by law or executive order to close in The City of New York.

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“Certificated Bond” means a certificated Bond registered in the name of the Holder thereof and issued in accordance with the Mortgage as heretofore amended and supplemented, substantially in the form of Exhibit A hereto, except that such Bond shall not bear the Global Bond Legend and shall not have the “Schedule of Exchanges of Interests in the Global Bond” attached thereto.

“Clearstream” means Clearstream Banking, societe anonyme.

“Depositary” has the meaning ascribed in Section 1.01 of this Twenty-sixth Supplemental Indenture.

“Distribution Compliance Period” means the 40-day distribution compliance period that extends through and including the 40th day after the later of the commencement of the offering of the Bonds and the closing date.

“Exchange Act” means the Securities Exchange Act of 1934, as amended.

“Exchange Bond” has the meaning ascribed in Section 1.04 of this Twenty-sixth Supplemental Indenture.

“Global Bonds” means, individually and collectively, each of the Restricted Global Bonds and the Unrestricted Global Bonds, substantially in the form of Exhibit A or B hereto issued in accordance with the Mortgage as heretofore amended and supplemented.

“Global Bond Legend” means the legend set forth in Section 2.08(b) hereof to be placed on all Global Bonds issued under this Twenty-sixth Supplemental Indenture.

“Holder” means a Person in whose name a Bond is registered.

“Indirect Participant” means a Person who holds a beneficial interest in a Global Bond through a Participant.

“Non-U.S. Person” means a Person who is not a U.S. Person.

“Participant” means, with respect to DTC, Euroclear or Clearstream, a Person who has an account with DTC, Euroclear or Clearstream, respectively (and, with respect to DTC, shall include Euroclear and Clearstream).

“Person” means an individual, partnership, corporation, limited liability company, unincorporated organization, association, joint-stock company, trust, joint venture, government, or any agency or political subdivision thereof or any other entity.

“Predecessor Bond” of any particular Bond means every previous Bond evidencing all or a portion of the same debt as that evidenced by such particular Bond; and, for the purposes of this definition, any Bond authenticated and delivered under Section 16 of the

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Indenture in exchange for or in lieu of a mutilated, destroyed, lost or stolen Bond shall be deemed to evidence the same debt as the mutilated, destroyed, lost or stolen Bond.

“Private Bond” has the meaning ascribed in Section 1.04 of this Twenty-sixth Supplemental Indenture.

“Private Placement Legend” means the legend set forth in Section 2.08(a) hereof to be placed on all Private Bonds issued under this Twenty-sixth Supplemental Indenture except as otherwise permitted by the provisions of this Twenty-sixth Supplemental Indenture.

“Record Date” means, with respect to any Interest Payment Date, the February 13 or August 15 (whether or not a Business Day), as the case may be, next preceding such Interest Payment Date.

“Registrar” means the Person appointed by the Company to maintain the Bond register, in which register, subject to such reasonable regulations as the Company may prescribe, the Company shall provide for the registration of Bonds and for the exchange and transfer of Bonds.

“Registration Rights Agreement” means the Registration Rights Agreement dated September 13, 2006 between the Company and the initial purchasers of the Bonds of the Twenty-eighth Series.

“Regulation S” means Regulation S promulgated under the Securities Act.

“Regulation S Global Bond” means a Regulation S Global Bond in the form of Exhibit A hereto bearing the Private Placement Legend, the Global Bond Legend and the Regulation S Global Bond Legend and deposited with and registered in the name of the Depositary or its nominee that will be issued in a denomination equal to the outstanding principal amount of the Bonds sold in reliance on Regulation S.

“Restricted Certificated Bond” means a Certificated Bond bearing the Private Placement Legend.

“Restricted Global Bond” means the 144A Global Bond and the Regulation S Global Bond, each of which shall bear the Private Placement Legend.

“Rule 144” means Rule 144 under the Securities Act.

“Rule 144A” means Rule 144A under the Securities Act.

“Rule 903” means Rule 903 under the Securities Act.

“Rule 904” means Rule 904 under the Securities Act.

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“Securities Act” means the Securities Act of 1933, as amended.

“Transfer Restricted Securities” means securities that bear or are required to bear the Private Placement Legend set forth in Section 2.08(a) hereof.

“Unrestricted Certificated Bond” means one or more Certificated Bonds that do not and are not required to bear the Private Placement Legend.

“Unrestricted Global Bond” means one or more Global Bonds, that do not and are not required to bear the Private Placement Legend and are deposited with, or in custody for, and registered in the name of the Depositary or its nominee.

“U.S. Person” means a U.S. person as defined in Rule 902(o) under the Securities Act.

ARTICLE IV

Reservation of Right to Make Amendments

Section 4.01.The Company reserves the right, without any consent or other action by holders of Bonds of the Twenty-eighth Series, or bonds of any subsequent series, to make such amendments to the Mortgage (as supplemented) as shall be necessary in order to cause there to be excluded from the Mortgaged and Pledged Property and the Lien of the Mortgage (as supplemented) at all times, including, without limitation, in the event and following the date that either or both of the Trustees or a receiver of trustee shall enter upon and take possession of the Mortgaged and Pledged Property in the manner provided in Article XIII of the Mortgage (as supplemented) by reason of the occurrence of a Default as defined in Section 65 thereof, all of the Company’s right, title and interest, whenever arising or acquired, in, to and under all accounts (as defined in the Uniform Commercial Code as in effect from time to time in the State of New York), all accounts receivable, all payments for goods sold or leased or for services rendered (whether or not they have been earned by performance), all rights in any merchandise or goods which any of the foregoing may represent, all rights, title, security and guaranties with respect to any or all of the foregoing, and all proceeds (as defined in the Uniform Commercial Code as in effect from time to time in the State of New York) of, and all collections from or with respect to, any or all of the foregoing.

Section 4.02The Company reserves the right, without any consent or other action by holders of Bonds of the Twenty-eighth Series, or holders of bonds of any subsequent series, to make the following amendments to Section 120 of the Mortgage (as supplemented): (i) to substitute for the words “adversely affecting any bonds then Outstanding hereunder”, which appear at the end of the last sentence of such Section, the words “which adversely affects the interests of the Holders of any of the bonds then Outstanding in any material respect” and (ii) to add at the end of the first sentence of such Section the following:

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or the Company may correct or supplement any provision herein or in any supplemental indenture which may be defective or inconsistent with any other provision herein or in any supplemental indenture; or the Company may make other changes to the provisions hereof or of any supplemental indenture or add new provisions hereto or to any supplemental indenture or eliminate provisions here from or from any supplemental indenture, provided that the same does not adversely affect the interests of the Holders of any of the bonds then Outstanding in any material respect.

ARTICLE V

Amendments to Mortgage

Section 5.01.So long as any of the Bonds of the Twenty-eighth Series remain Outstanding, Section 7 of the Mortgage is amended by adding at the end thereof the following additional paragraphs:

If any bonds Outstanding at the date of a Net Earning Certificate (except any for the refunding of which the bonds applied for are to be issued) or any bonds then applied for in pending applications (including the application in connection with which such Net Earning Certificate is made) bear or are to bear interest at a variable rate or variable rates such that the interest requirements with respect to such bonds for any twelve (12) month period prior to the stated maturity date of such bonds are not determinable at the date of such Net Earning Certificate (any such bonds being referred to as “Variable Rate Bonds”), then (in lieu of setting forth the Annual Interest Requirements (as otherwise prescribed by this Section 7), such Net Earning Certificate shall (A) set forth (i) the sum of the amounts required by clauses (i) through (iv) of paragraph (B) of this Section 7 (in the case of such clauses (i) and (ii), excluding the interest requirements in respect of the Variable Rate Bonds) (the sum of such amounts being referred to herein and to be referred to in such Net Earning Certificate as the “Fixed Rate Interest Amount”), and (ii) the amount (referred to herein and to be referred to in such Net Earning Certificate as the “Maximum Permitted Variable Rate Interest Amount”) by which (x) one-half of the Adjusted Net Earnings of the Company set forth in such Net Earning Certificate, exceeds (y) the Fixed Rate Interest Amount set forth in such Net Earning Certificate, and (ii) if such Net Earning Certificate is accompanied by a certificate of an independent (as hereinafter defined) investment banking firm, signed by a managing director or officer thereof, to the effect that, based upon historical fluctuations in the indices upon which the variable rate or variable rates home by the Variable Rate Bonds are based, and taking into account the margins to be added to or subtracted from such indices and/or any other adjustments to be made in determining such variable rate or variable rates and prevailing and projected conditions in the markets

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influencing such indices, such independent (as hereinafter defined) investment banking firm believes (or is of the view), as of the date of such certificate, that the aggregate amount of interest to be payable on all of the Variable Rate Bonds during any period of twelve (12) months prior to the stated maturity date last to occur of any of the Variable Rate Bonds will not exceed the Maximum Permitted Variable Rate Interest Amount (as calculated by the Company in such Net Earning Certificate without any responsibility on the part of such independent (as hereinafter defined) investment banking firm for the calculation thereof), such Net Earning Certificate shall be deemed for all purposes of the Mortgage (including, without limitation, Sections 26, 28 and 29 of the Mortgage) to show Adjusted Net Earnings of the Company to be as required by Section 27 of the Mortgage. As used in this Section 7, “independent” means, with respect to an investment banking firm that provides a certificate pursuant to this Section 7, that: (i) such investment banking firm is competent to provide such certificate (and such investment banking firm shall be conclusively presumed to be competent to provide such certificate if such investment banking firm is an investment banking firm of nationally recognized standing and engages in interest rate swap transactions in the ordinary course of its business); (ii) such investment banking firm does not have any direct or indirect investment in the Company or in any bonds that, as of the date of such certificate, are Outstanding or the subject of a pending application for authentication and delivery under the Mortgage (including, without limitation, any bonds that are subject of the Net Earning Certificate to which such certificate relates) or in any affiliate of the Company (other than de minimus amounts of loans or securities of the Company or affiliates of the Company held in its or its affiliates’ accounts and any investment in, or ownership of, additional securities or loans of the Company or affiliates of the Company resulting from its market making activities in the ordinary course of its business); (iii) such investment banking firm is not, and none of its officers or directors is, an affiliate of the Company; and (iv) such investment banking firm is not acting as an underwriter with respect to any bonds that are the subject of the Net Earning Certificate to which such certificate relates or as an arranger or provider of the loans, extensions of credit or other securities (if any) for which such bonds are collateral security.

If the Company is a successor corporation (within the meaning of Section 86 of this Indenture), the “Adjusted Net Earrings of the Company” as set forth in each Net Earning Certificate shall be calculated as described in the last two sentences of Section 86 of this Indenture.

Section 5.02.So long as any of the Bonds of the Twenty-eighth Series remain Outstanding, Section 27 of the Mortgage is amended by adding at the end thereof the following additional sentence:

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As described in the penultimate paragraph of Section 7 hereof, and subject to the conditions therein specified, a Net Earning Certificate shall be deemed to show Adjusted Net Earnings of the Company to be as required by this Section 27 (without any necessity for such Net Earning Certificate to specify Annual Interest Requirements).

Section 5.03.So long as any of the Bonds of the Twenty-eighth Series are Outstanding, Section 86 of the Mortgage is amended by adding at the end thereof the following additional sentences:

For the avoidance of any doubt, it is expressly stated that in the event that a successor corporation (having succeeded to and having been substituted for the Company in accordance with this Section 86) shall exercise any right under this Indenture (whether as to the issuance of additional bonds (including, without limitation, the Bonds of the Twenty-eighth), the withdrawal of cash, the release of property, the taking of credit under Section 39 or Section 40 hereof, or otherwise) and a Net Earning Certificate shall be required by the terms of this Indenture in connection therewith, the “Adjusted Net Earnings of the Company” shall be, and shall be stated in such Net Earning Certificate to be, the lesser of (A) the amount (for the applicable period selected in accordance with paragraph (A) of Section 7 of this Indenture) determined in accordance with paragraph (A) of Section 7 of this Indenture (and the other provisions of such Section 7 that are relevant to such paragraph) on the basis of (i) the items set forth in clauses (1), (2), (4) and (6) of paragraph (A) of such Section 7 being such portions of such items of such successor corporation as are reasonably allocated by such successor corporation to or from the Mortgaged and Pledged Property as a plant or plants and an operating system or operating systems (and if, on the date of a Net Earning Certificate, such successor corporation shall be a party to any other general or first mortgage indenture and deed of trust relating to property other than the Mortgaged and Pledged Property and the lien of such other mortgage indenture and deed of trust shall not have been discharged, such reasonable allocation shall be in a manner consistent with the manner of allocation utilized and/or to be utilized by such successor corporation in making calculations of the “Adjusted Net Earnings of the Company” (or other comparable term) under and as defined in such other mortgage indenture and deed of trust), (ii) the item set forth in clause (8) of paragraph (A) of such Section 7 being calculated without regard to income (net) derived from any electric and/or gas utility business of the successor corporation in which the Mortgaged and Pledged Property is not utilized (but otherwise in accordance with such Section 7), and (iii) the item set forth in clause (10) of paragraph (A) of such Section 7 being calculated without regard to sub-clause (b) of such clause and without regard to the proviso to such clause (but otherwise in accordance with such clause), and (B) the amount (for the applicable period

35

selected in accordance with paragraph (A) of Section 7 of this Indenture) determined in accordance with paragraph (A) of Section 7 of this Indenture (and the other provisions of such Section 7 that are relevant to such paragraph) (without any allocation or distinction as to the derivation of the items set forth in any of the clauses of paragraph (A) of such Section 7, other than allocation or distinction between (i) the electric and/or gas utility business or businesses in which such successor corporation is engaged (whether or not the Mortgaged and Pledged Property is utilized in connection therewith), and (ii) the other business or businesses in which such successor corporation is engaged (with such other business or businesses being given effect under the items set forth in clauses (8) and (10) of paragraph (A) of such Section 7)). Each such Net Earning Certificate shall contain a statement of the signers of such Net Earning Certificate that, in the opinion of such signers, the allocations made in the calculations of “Adjusted Net Earnings of the Company” as set forth in such Net Earning Certificate are in accordance with the requirements of the preceding sentence of this Section 86.

Section 5.04For so long as any Bonds of the Twenty-eighth Series are Outstanding, the Company shall not subject, or permit to be subjected, any Mortgaged and Pledged Property under the Mortgage to the lien of the Company’s General Mortgage Indenture and Deed of Trust dated as of August 1, 1993, as amended and supplemented.

ARTICLE VI

Miscellaneous Provisions

Section 6.01. Subject to the amendments provided for in this Twenty-sixth Supplemental Indenture, the terms defined in the Mortgage, as heretofore supplemented, shall, for all purposes of this Twenty-sixth Supplemental Indenture, have the meanings specified in the Mortgage, as heretofore supplemented.

Section 6.02. The Trustees hereby accept the trusts herein declared, provided, created or supplemented and agree to perform the same upon the terms and conditions herein and in the Mortgage, as heretofore supplemented, set forth and upon the following terms and conditions:

The Trustees shall not be responsible in any manner whatsoever for or in respect of the validity or sufficiency of this Twenty-sixth Supplemental Indenture or for or in respect of the recitals contained herein, all of which recitals are made by the Company solely. In general, each and every term and condition contained in Article XVII of the Mortgage shall apply to and form part of this Twenty-sixth Supplemental Indenture with the same force and effect as if the same were herein set forth in full with such omissions, variations and

36

insertions, if any, as may be appropriate to make the same conform to the provisions of this Twenty-sixth Supplemental Indenture.

Section 6.03. Whenever in this Twenty-sixth Supplemental Indenture any of the parties hereto is named or referred to, this shall, subject to the provisions of Articles XVI and XVII of the Mortgage, be deemed to include the successors and assigns of such party, and all the covenants and agreements in this Twenty-sixth Supplemental Indenture contained by or on behalf of the Company, or by or on behalf of the Trustees shall, subject as aforesaid, bind and inure to the respective benefit of the respective successors and assigns of such parties, whether so expressed or not.

Section 6.04. Nothing in this Twenty-sixth Supplemental Indenture, expressed or implied, is intended, or shall be construed, to confer upon, or to give to, any person, firm or corporation, other than the parties hereto and the holders of the bonds and coupons Outstanding under the Indenture, any right, remedy or claim under or by reason of this Twenty-sixth Supplemental Indenture or any covenant, condition, stipulation, promise or agreement hereof, and all the covenants, conditions, stipulations, promises and agreements in this Twenty-sixth Supplemental Indenture contained by or on behalf of the Company shall be for the sole and exclusive benefit of the parties hereto, and of the holders of the bonds and coupons Outstanding under the Indenture.

Section 6.05. This Twenty-sixth Supplemental Indenture shall be executed in several counterparts, each of which shall be an original and all of which shall constitute but one and the same instrument.

[Signature Page to Follow]

37

IN WITNESS WHEREOF, NORTHWESTERN CORPORATION has caused its corporate name to be hereunto affixed, and this instrument to be signed and sealed by one of its Vice Presidents, and its seal to be attested by its Corporate Secretary or one of its Corporate Assistant Secretaries for and in its behalf, and THE BANK OF NEW YORK, in token of its acceptance of the trust hereby created, has caused its corporate name to be hereunto affixed, and this instrument to be signed and sealed by one of its Vice Presidents or one of its Assistant Vice Presidents, and its corporate seal to be attested by one of its Assistant Vice Presidents, Assistant Secretaries or Assistant Treasurers, and Ming Ryan, for all like purposes, has hereunto set her hand and affixed her seal, as of the day and year first above written.

NORTHWESTERN CORPORATION

By: /s/ Brian B. Bird

[Vice President]

[SEAL]

Attest:

/s/ Michael J. Young

[Assistant Secretary]

Executed, sealed and delivered by

NORTHWESTERN CORPORATION

in the presence of:

/s/ Tamra F. Lydic

/s/ Emily Larkin

[Signature Page to the Twenty-sixth Supplemental Indenture]

38

STATE OF SOUTH DAKOTA )

	) ss.
COUNTY OF LINCOLN	)

This instrument was acknowledged before me on this 13th day of September, 2006, by Brian B. Bird, Vice President, of NORTHWESTERN CORPORATION, a Delaware corporation.

/s/ Kathy Lambertz

Notary Public

[SEAL]

[Signature Page to the Twenty-sixth Supplemental Indenture]

39

THE BANK OF NEW YORK,

as Corporate Trustee

By: /s/ Alexander Pabon

Name: Alexander Pabon

Title: Assistant Vice President

[SEAL]

Attest:

/s/ Jeremy Finkelstein

Name: Jeremy Finkelstein

Title: Assistant Vice President

/s/ Ming Ryan

Ming Ryan, as Co-Trustee

Executed, sealed and delivered by

THE BANK OF NEW YORK and

Ming Ryan in the presence of:

/s/ Franca M. Ferrera

/s/ Robert A. Massimillo

[Signature Page to the Twenty-sixth Supplemental Indenture]

40

STATE OF NEW YORK)

	) ss.
COUNTY OF NEW YORK	)

This instrument was acknowledged before me on this 8th day of September, 2006, by Alexander Pabon, Assistant Treasurer of THE BANK OF NEW YORK, a New York corporation.

/s/ Carlos R. Luciano

Notary Public

[Signature Page to the Twenty-sixth Supplemental Indenture]

41

STATE OF NEW YORK)

	) ss.
COUNTY OF NEW YORK	)

This instrument was acknowledged before me on this 8th day of September, 2006, by MING RYAN.

/s/ Carlos R. Luciano

Notary Public

[Signature Page to the Twenty-sixth Supplemental Indenture]

42

EXHIBIT A

FORM OF PRIVATE BOND

(FACE OF BOND)

[Insert the Global Bond Legend, if applicable, pursuant to the provisions of the Twenty-Sixth Supplemental Indenture]

[Insert the Private Placement Legend, if applicable, pursuant to the provisions of the Twenty-Sixth Supplemental Indenture]

[Insert the Reg S Global Bond Legend, if applicable, pursuant to the provisions of the Twenty-Sixth Supplemental Indenture]

NORTHWESTERN CORPORATION

FIRST MORTGAGE BOND, 6.04% SERIES DUE 2016

No. [T] R- CUSIP: ___________ $______________

NORTHWESTERN CORPORATION, a corporation organized and existing under the Laws of the State of Delaware (hereinafter called the Company), for value received, hereby promises to pay to ______________________ or its registered assigns, on September 1, 2016, at the office or agency of the Company in the Borough of Manhattan, The City of New York, $______________ dollars in such coin or currency of the United States of America as at the time of payment is legal tender for public and private debts, and to pay to the registered owner hereof interest thereon from the date of first authentication of Bonds of the series herein designated, at the rate per annum of 6.04%, plus Additional Interest, if applicable, pursuant to the Registration Rights Agreement (as hereinafter defined) in like coin or currency at such office or agency on March 1 and September 1 in each year, until the Company’s obligation with respect to the payment of such principal shall have been discharged.

This Bond is issued by the Company pursuant to the Twenty-Sixth Supplemental Indenture (described on the reverse hereof). The terms of this Bond shall be those specified herein and pursuant to the Mortgage (as hereinafter defined), as heretofore amended and supplemented, including by the Twenty-Sixth Supplemental Indenture.

The provisions of this Bond are continued on the reverse hereof and such continued provisions shall for all purposes have the same effect as though set fully forth at this place.

A-1

This Bond shall not become obligatory until The Bank of New York (successor to Morgan Guaranty Trust Company of New York), the Corporate Trustee under the Mortgage, or its successor thereunder, shall have signed the form of authentication certificate endorsed hereon.

A-2

IN WITNESS WHEREOF, NORTHWESTERN CORPORATION has caused this instrument to be signed in its corporate name by its Chairman of the Board or its President or one of its Vice-Presidents by his signature or a facsimile thereof, and its corporate seal to be impressed or imprinted hereon and attested by its Secretary or one of its Assistant Secretaries by his/her signature or a facsimile thereof.

Dated: September ____, 2006.

NORTHWESTERN CORPORATION

By ____________________________

Attest: ____________________________

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CORPORATE TRUSTEE’S AUTHENTICATION CERTIFICATE

This Bond is one of the Bonds, of the series herein designated, described or provided for in the within-mentioned Mortgage.

THE BANK OF NEW YORK,
	as Corporate Trustee

By ____________________________
	Authorized Signatory

A-4

(REVERSE OF BOND)

General

This Bond is one of an issue of Bonds of the Company issuable in series and is one of a series known as its First Mortgage Bonds, 6.04% Series due 2016, all Bonds of all series issued and to be issued under and equally secured (except in so far as any sinking or other fund, established in accordance with the provisions of the Mortgage hereinafter mentioned, may afford additional security for the Bonds of any particular series) by a Mortgage and Deed of Trust (herein, together with any indenture supplemental thereto, called the Mortgage), dated as of October 1, 1945, executed by the Company to Guaranty Trust Company of New York (The Bank of New York, successor) and Arthur E. Burke (Ming Ryan, successor), as Trustees. Reference is made to the Mortgage for a description of the property mortgaged and pledged, the nature and extent of the security, the rights of the holders of the Bonds and of the Trustees in respect thereof, the duties and immunities of the Trustees and the terms and conditions upon which the Bonds are and are to be secured and the circumstances under which additional Bonds may be issued. With the consent of the Company and to the extent permitted by and as provided in the Mortgage, the rights and obligations of the Company and/or the rights of the holders of the Bonds and/or coupons and/or the terms and provisions of the Mortgage may be modified or altered by affirmative vote of the holders of at least 66 2/3% in principal amount of the Bonds then outstanding under the Mortgage and, if the rights of the holders of one or more, but less than all, series of Bonds then outstanding are to be affected, then also by affirmative vote of the holders of at least 66 2/3% in principal amount of the Bonds then outstanding of each series of Bonds so to be affected (excluding in any case Bonds disqualified from voting by reason of the Companys interest therein as provided in the Mortgage); provided that, without the consent of the holder hereof, no such modification or alteration shall, among other things, impair or affect the right of the holder to receive payment of the principal of (and premium, if any) and interest on this Bond, on or after the respective due dates expressed herein, or permit the creation of any lien equal or prior to the lien of the Mortgage or deprive the holder of the benefit of a lien on the mortgaged and pledged property.

The principal hereof may be declared or may become due prior to the maturity date hereinbefore named on the conditions, in the manner and at the time set forth in the Mortgage, upon the occurrence of a default as in the Mortgage provided.

This Bond is transferable as prescribed in the Mortgage by the registered owner hereof in person, or by his duly authorized attorney, at the office or agency of the Company in the Borough of Manhattan, The City of New York, upon surrender and cancellation of this Bond, and upon payment, if the Company shall require it, of the transfer charges provided for in the Mortgage, and, thereupon, a new fully registered Bond of the same series for a like principal amount will be issued to the transferee in exchange herefor as provided in the Mortgage; provided that, this Bond shall also be subject to the restrictions on

A-5

transfer and exchange that appear above. The Company and the Trustees may deem and treat the person in whose name this Bond is registered as the absolute owner hereof for the purpose of receiving payment and for all other purposes and neither the Company nor the Trustees shall be affected by any notice to the contrary.

In the manner prescribed in the Mortgage, any Bonds of this series, upon surrender thereof, for cancellation, at the office or agency of the Company in the Borough of Manhattan, The City of New York, are exchangeable for a like aggregate principal amount of registered Bonds of the same series of other authorized denominations.

The Company shall not be required (A) to issue, to register the transfer of or to exchange Bonds during a period beginning at the opening of business 15 days before the day of any selection of Bonds for redemption under Section 1.02 of the Twenty-Sixth Supplemental Indenture (as hereinafter defined) and ending at the close of business on the day of selection or (B) to register the transfer of or to exchange any Bond so selected for redemption in whole or in part, except the unredeemed portion of any Bond being redeemed in part.

No recourse shall be had for the payment of the principal of or interest on this Bond against any incorporator or any past, present or future subscriber to the capital stock, stockholder, officer or director of the Company or of any predecessor or successor corporation, as such, either directly or through the Company or any predecessor or successor corporation, under any rule of law, statute or constitution or by the enforcement of any assessment or otherwise, all such liability of incorporators, subscribers, stockholders, officers and directors being released by the holder or owner hereof by the acceptance of this Bond and being likewise waived and released by the terms of the Mortgage.

Capitalized terms used in this Bond shall have the meanings ascribed to them in the Twenty-Sixth Supplemental Indenture.

Interest

The Bonds shall bear interest for each Interest Period (as hereinafter defined) at a rate per annum of ____% (the “Interest Rate”), as set forth in Section 1.01 of the Twenty-Sixth Supplemental Indenture, dated as of September 1, 2006, between the Company and the Trustees (such supplemental indenture, the “Twenty-Sixth Supplemental Indenture”), plus Additional Interest, if applicable, as set forth in the Registration Rights Agreement.

The period commencing on an Interest Payment Date and ending on the day preceding the next succeeding Interest Payment Date shall be an “Interest Period,” provided that the first Interest Period shall begin on the date of the first authentication of the Bonds and extend through February 28, 2007, the day preceding the first Interest Payment Date.

A-6

Interest payments for the Bonds will be computed and paid on the basis of a 360-day year of twelve 30-day months. If an Interest Payment Date or Redemption Date falls on a day that is not a Business Day, such Interest Payment Date or Redemption Date, as the case may be, will be the immediately succeeding Business Day with the same force and effect as if made on the original Interest Payment Date or Redemption Date, as the case may be, and no interest shall accrue for the period from and after such original Interest Payment Date or Redemption Date, as the case may be. All dollar amounts resulting from such calculation will be rounded, if necessary, to the nearest cent with one-half cent rounded upward.

Interest on any Bond which is payable, and is punctually paid or duly provided for, on any Interest Payment Date shall be paid to the Person in whose name that Bond (or one or more Predecessor Bonds) is registered at the close of business on the Record Date for such interest; provided, however, that interest payable at maturity (whether the stated maturity or maturity resulting from declaration of acceleration, call for redemption or otherwise) shall be payable to the Person to whom the principal of such Bond shall be payable.

Redemption

The Bonds shall be redeemable at the option of the Company in whole or in part at anytime and from time to time, prior to maturity, upon notice to the holders of such Bonds by first class mail, mailed not less than 30 days but not more than 60 days prior to the date on which such Bonds are fixed to be redeemed (such date fixed for redemption, the “Redemption Date”), in cash at a redemption price (the “Redemption Price”) equal to (i) the greater of: (A) one hundred per centum (100%) of the principal amount of Bonds to be redeemed then Outstanding, and (B) the sum of the present values of the remaining scheduled payments of principal and interest on such Bonds to be redeemed (not including any portion of such payments of interest accrued as of the Redemption Date) discounted to the Redemption Date on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months) at the Adjusted Treasury Rate, plus 20 basis points, plus (ii) accrued and unpaid interest to the Redemption Date, as calculated by an Independent Investment Banker.

“Adjusted Treasury Rate” means, with respect to any Redemption Date:

• the yield, under the heading which represents the average for the immediately preceding week, appearing in the most recently published statistical release designated “H.15(519)” or any successor publication which is published weekly by the Board of Governors of the Federal Reserve System and which establishes yields on actively traded United States Treasury securities adjusted to constant maturity under the caption “Treasury Constant Maturities” for the maturity corresponding to the Comparable Treasury Issue (as hereinafter defined) (if no maturity is within three months before or after the Remaining Life (as hereinafter

A-7

defined), yields for the two published maturities most closely corresponding to the Comparable Treasury Issue will be determined and the Adjusted Treasury Rate will be interpolated or extrapolated from such yields on a straight line basis, rounding to the nearest month); or

• if such release (or any successor release) is not published during the week preceding the calculation date or does not contain such yields, the rate per annum equal to the semi-annual equivalent yield to maturity of the Comparable Treasury Issue, calculated using a price for the Comparable Treasury Issue (expressed as a percentage of its principal amount) equal to the Comparable Treasury Price (as hereinafter defined) for such Redemption Date.

The Adjusted Treasury Rate will be calculated on the third Business Day (as hereinafter defined) preceding the Redemption Date.

“Comparable Treasury Issue” the United States Treasury security selected by an Independent Investment Banker (as hereinafter defined) as having a maturity comparable to the remaining term of the Bonds to be redeemed that would be used, at the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of comparable maturity to the remaining term of such Bonds (the “Remaining Life”).

“Comparable Treasury Price” means (1) the average of five Reference Treasury Dealer Quotations (as hereinafter defined) for such Redemption Date, after excluding the highest and lowest Reference Treasury Dealer Quotations, or (2) if the Independent Investment Banker (as hereinafter defined) obtains fewer than five such Reference Treasury Dealer Quotations, the average of all such quotations.

“Independent Investment Banker” means Credit Suisse Securities (USA) LLC and its successors, or if that firm is unwilling or unable to serve as such, an independent investment and banking institution of national standing appointed by the Company.

“Reference Treasury Dealer” means:

• Credit Suisse Securities (USA) LLC and its successors; provided that, if Credit Suisse Securities (USA) LLC ceases to be a primary U.S. Government securities dealer in New York City (Primary Treasury Dealer), another Primary Treasury Dealer appointed by the Company; and

• up to four other Primary Treasury Dealers selected by the Company.

“Reference Treasury Dealer Quotations” means, with respect to each Reference Treasury Dealer and any Redemption Date, the average, as determined by the Independent Investment Banker, of the bid and asked prices for the Comparable Treasury Issue (expressed

A-8

in each case as a percentage of its principal amount) quoted in writing to the Independent Investment Banker at 5:00 p.m., New York City time, on the third Business Day preceding such Redemption Date.

The Corporate Trustee shall be under no duty to inquire into, may conclusively presume the correctness of, and shall be fully protected in acting upon the calculation by the Independent Investment Banker of any Redemption Price of the Bonds.

A-9

INSTRUMENT OF ASSIGNMENT AND TRANSFER

FOR VALUE-RECEIVED the undersigned hereby sell(s), assign(s) and transfer(s) unto

Identifying Number of Assignee _________________________________________________

__________________________________________________________________________________

__________________________________________________________________________________

__________________________________________________________________________________

(Please print or typewrite name and address,

including zip code of Assignee)

the within Bond and all rights thereunder, hereby irrevocably constituting and appointing _____ attorney to transfer said Bond on the books of the Company, with full power of substitution in the premises.

Dated: ____________________________

___________________________________

Name:

NOTICE: The signature to this assignment must correspond with the name as written upon the first page of the within instrument in every particular, without alteration or enlargement or any change whatsoever.

__________________________

Signature Guarantee

SIGNATURE GUARANTEE

Signatures must be guaranteed by an “eligible guarantor institution” meeting the requirements of the Registrar, which requirements include membership or participation in the Security Transfer Agent Medallion Program (“STAMP”) or such other “signature guarantee program” as may be determined by the Registrar in addition to, or in substitution for, STAMP, all in accordance with the Securities Exchange Act of 1934, as amended.

A-10

SCHEDULE OF EXCHANGES OF INTERESTS IN THE GLOBAL BOND

The following exchanges of a part of this Global Bond for an interest in another Global Bond or for a Certificated Bond, or exchanges of a part of another Global Bond or Certificated Bond for an interest in this Global Bond, have been made:

Date of
Exchange Amount of
decrease in
Principal
Amount of this
Global Bond Amount of
increase in
Principal
Amount of this
Global Bond Principal
Amount of this
Global Bond
following such
decrease
(or increase) Signature of
authorized
officer of
Corporate
Trustee or Bond
Custodian

_________________________

This should be included only if the Bond is issued in global form.

A-11

EXHIBIT B

FORM OF EXCHANGE BOND

(FACE OF BOND)

[Insert the Global Bond Legend, if applicable, pursuant to the provisions of the Twenty-Sixth Supplemental Indenture]

NORTHWESTERN CORPORATION

FIRST MORTGAGE BOND, 6.04% SERIES DUE 2016

No. [T] R- CUSIP: ___________ $______________

NORTHWESTERN CORPORATION, a corporation organized and existing under the Laws of the State of Delaware (hereinafter called the Company), for value received, hereby promises to pay to ______________________ or its registered assigns, on September 1, 2016, at the office or agency of the Company in the Borough of Manhattan, The City of New York, $______________ dollars in such coin or currency of the United States of America as at the time of payment is legal tender for public and private debts, and to pay to the registered owner hereof interest thereon from the date of first authentication of Bonds of the series herein designated, at the rate per annum of 6.04%, plus Additional Interest, if applicable, pursuant to the Registration Rights Agreement, in like coin or currency at such office or agency on March 1 and September 1 in each year, until the Company’s obligation with respect to the payment of such principal shall have been discharged.

This Bond is issued by the Company pursuant to the Twenty-Sixth Supplemental Indenture (described on the reverse hereof). The terms of this Bond shall be those specified herein and pursuant to the Mortgage (as hereinafter defined), as heretofore amended and supplemented, including by the Twenty-Sixth Supplemental Indenture.

The provisions of this Bond are continued on the reverse hereof and such continued provisions shall for all purposes have the same effect as though set fully forth at this place.

This Bond shall not become obligatory until The Bank of New York (successor to Morgan Guaranty Trust Company of New York), the Corporate Trustee under the Mortgage, or its successor thereunder, shall have signed the form of authentication certificate endorsed hereon.

B-1

IN WITNESS WHEREOF, NORTHWESTERN CORPORATION has caused this instrument to be signed in its corporate name by its Chairman of the Board or its President or one of its Vice-Presidents by his signature or a facsimile thereof, and its corporate seal to be impressed or imprinted hereon and attested by its Secretary or one of its Assistant Secretaries by his/her signature or a facsimile thereof.

Dated: ________________.

NORTHWESTERN CORPORATION

By ____________________________

Attest: ____________________________

B-2

CORPORATE TRUSTEES AUTHENTICATION CERTIFICATE

This Bond is one of the Bonds, of the series herein designated, described or provided for in the within-mentioned Mortgage.

THE BANK OF NEW YORK,

as Corporate Trustee

By ____________________________

Authorized Signatory

B-3

(REVERSE OF BOND)

General

This Bond is one of an issue of Bonds of the Company issuable in series and is one of a series known as its First Mortgage Bonds, 6.04% Series due 2016, all Bonds of all series issued and to be issued under and equally secured (except in so far as any sinking or other fund, established in accordance with the provisions of the Mortgage hereinafter mentioned, may afford additional security for the Bonds of any particular series) by a Mortgage and Deed of Trust (herein, together with any indenture supplemental thereto, called the Mortgage), dated as of October 1, 1945, executed by the Company to Guaranty Trust Company of New York (The Bank of New York, successor) and Arthur E. Burke (Ming Ryan, successor), as Trustees. Reference is made to the Mortgage for a description of the property mortgaged and pledged, the nature and extent of the security, the rights of the holders of the Bonds and of the Trustees in respect thereof, the duties and immunities of the Trustees and the terms and conditions upon which the Bonds are and are to be secured and the circumstances under which additional Bonds may be issued. With the consent of the Company and to the extent permitted by and as provided in the Mortgage, the rights and obligations of the Company and/or the rights of the holders of the Bonds and/or coupons and/or the terms and provisions of the Mortgage may be modified or altered by affirmative vote of the holders of at least 66 2/3% in principal amount of the Bonds then outstanding under the Mortgage and, if the rights of the holders of one or more, but less than all, series of Bonds then outstanding are to be affected, then also by affirmative vote of the holders of at least 66 2/3% in principal amount of the Bonds then outstanding of each series of Bonds so to be affected (excluding in any case Bonds disqualified from voting by reason of the Companys interest therein as provided in the Mortgage); provided that, without the consent of the holder hereof, no such modification or alteration shall, among other things, impair or affect the right of the holder to receive payment of the principal of (and premium, if any) and interest on this Bond, on or after the respective due dates expressed herein, or permit the creation of any lien equal or prior to the lien of the Mortgage or deprive the holder of the benefit of a lien on the mortgaged and pledged property.

The principal hereof may be declared or may become due prior to the maturity date hereinbefore named on the conditions, in the manner and at the time set forth in the Mortgage, upon the occurrence of a default as in the Mortgage provided.

This Bond is transferable as prescribed in the Mortgage by the registered owner hereof in person, or by his duly authorized attorney, at the office or agency of the Company in the Borough of Manhattan, The City of New York, upon surrender and cancellation of this Bond, and upon payment, if the Company shall require it, of the transfer charges provided for in the Mortgage, and, thereupon, a new fully registered Bond of the same series for a like principal amount will be issued to the transferee in exchange herefor as provided in the Mortgage; provided that, this Bond shall also be subject to the restrictions on

B-4

transfer and exchange that appear above. The Company and the Trustees may deem and treat the person in whose name this Bond is registered as the absolute owner hereof for the purpose of receiving payment and for all other purposes and neither the Company nor the Trustees shall be affected by any notice to the contrary.

In the manner prescribed in the Mortgage, any Bonds of this series, upon surrender thereof, for cancellation, at the office or agency of the Company in the Borough of Manhattan, The City of New York, are exchangeable for a like aggregate principal amount of registered Bonds of the same series of other authorized denominations.

The Company shall not be required (A) to issue, to register the transfer of or to exchange Bonds during a period beginning at the opening of business 15 days before the day of any selection of Bonds for redemption under Section 2.02 of the Twenty-Sixth Supplemental Indenture (as hereinafter defined) and ending at the close of business on the day of selection or (B) to register the transfer of or to exchange any Bond so selected for redemption in whole or in part, except the unredeemed portion of any Bond being redeemed in part.

No recourse shall be had for the payment of the principal of or interest on this Bond against any incorporator or any past, present or future subscriber to the capital stock, stockholder, officer or director of the Company or of any predecessor or successor corporation, as such, either directly or through the Company or any predecessor or successor corporation, under any rule of law, statute or constitution or by the enforcement of any assessment or otherwise, all such liability of incorporators, subscribers, stockholders, officers and directors being released by the holder or owner hereof by the acceptance of this Bond and being likewise waived and released by the terms of the Mortgage.

This Bond shall not become obligatory until The Bank of New York, the Corporate Trustee under the Mortgage, or its successor thereunder, shall have signed the form of authentication certificate endorsed hereon.

The Corporate Trustee shall be under no duty to inquire into, may conclusively presume the correctness of, and shall be fully protected in acting upon the calculation by the Independent Investment Banker of any Redemption Price of the Bonds.

Capitalized terms used in this Bond shall have the meanings ascribed to them in the Twenty-Sixth Supplemental Indenture.

Interest

The Bonds shall bear interest for each Interest Period (as hereinafter defined) at a rate per annum of 6.04% (the “Interest Rate”), as set forth in Section 2.01 of the Twenty-Sixth Supplemental Indenture, dated as of September 1, 2006, between the Company and the Trustees (such supplemental indenture, the “Twenty-Sixth Supplemental Indenture”), plus Additional Interest, if applicable, pursuant to the Registration Rights Agreement.

B-5

The period commencing on an Interest Payment Date and ending on the day preceding the next succeeding Interest Payment Date shall be an “Interest Period,” provided that the first Interest Period shall begin on the date of the first authentication of the Bonds and extend through ________________, the day preceding the next Interest Payment Date.

Interest payments for the Bonds will be computed and paid on the basis of a 360day year of twelve 30-day months. If an Interest Payment Date or Redemption Date falls on a day that is not a Business Day, such Interest Payment Date or Redemption Date, as the case may be, will be the immediately succeeding Business Day with the same force and effect as if made on the original Interest Payment Date or Redemption Date, as the case may be, and no interest shall accrue for the period from and after such original Interest Payment Date or Redemption Date, as the case may be. All dollar amounts resulting from such calculation will be rounded, if necessary, to the nearest cent with one-half cent rounded upward.

Interest on any Bond which is payable, and is punctually paid or duly provided for, on any Interest Payment Date shall be paid to the Person in whose name that Bond (or one or more Predecessor Bonds) is registered at the close of business on the Record Date for such interest; provided, however, that interest payable at maturity (whether the stated maturity or maturity resulting from declaration of acceleration, call for redemption or otherwise) shall be payable to the Person to whom the principal of such Bond shall be payable.

Redemption

The Bonds Series shall be redeemable at the option of the Company in whole or in part at anytime and from time to time, prior to maturity, upon notice to the holders of such Bonds by first class mail, mailed not less than 30 days but not more than 60 days prior to the date on which such Bonds are fixed to be redeemed (such date fixed for redemption, the “Redemption Date”), in cash at a redemption price (the “Redemption Price”) equal to (i) the greater of: (A) one hundred per centum (100%) of the principal amount of Bonds to be redeemed then Outstanding, and (B) the sum of the present values of the remaining scheduled payments of principal and interest on such Bonds to be redeemed (not including any portion of such payments of interest accrued as of the Redemption Date) discounted to the Redemption Date on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months) at the Adjusted Treasury Rate, plus 20 basis points, plus (ii) accrued and unpaid interest to the Redemption Date, as calculated by an Independent Investment Banker.

“Adjusted Treasury Rate” means, with respect to any Redemption Date:

• the yield, under the heading which represents the average for the immediately preceding week, appearing in the most recently published statistical release designated “H.15(519)” or any successor publication which is published weekly by the Board of Governors of the Federal

B-6

Reserve System and which establishes yields on actively traded United States Treasury securities adjusted to constant maturity under the caption “Treasury Constant Maturities” for the maturity corresponding to the Comparable Treasury Issue (as hereinafter defined) (if no maturity is within three months before or after the Remaining Life (as hereinafter defined), yields for the two published maturities most closely corresponding to the Comparable Treasury Issue will be determined and the Adjusted Treasury Rate will be interpolated or extrapolated from such yields on a straight line basis, rounding to the nearest month); or

• if such release (or any successor release) is not published during the week preceding the calculation date or does not contain such yields, the rate per annum equal to the semi-annual equivalent yield to maturity of the Comparable Treasury Issue, calculated using a price for the Comparable Treasury Issue (expressed as a percentage of its principal amount) equal to the Comparable Treasury Price (as hereinafter defined) for such Redemption Date.

The Adjusted Treasury Rate will be calculated on the third Business Day (as hereinafter defined) preceding the Redemption Date.

“Comparable Treasury Issue” the United States Treasury security selected by an Independent Investment Banker (as hereinafter defined) as having a maturity comparable to the remaining term of the Bonds to be redeemed that would be used, at the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of comparable maturity to the remaining term of such Bonds (the “Remaining Life”).

“Comparable Treasury Price” means (1) the average of five Reference Treasury Dealer Quotations (as hereinafter defined) for such Redemption Date, after excluding the highest and lowest Reference Treasury Dealer Quotations, or (2) if the Independent Investment Banker (as hereinafter defined) obtains fewer than five such Reference Treasury Dealer Quotations, the average of all such quotations.

“Independent Investment Banker” means Credit Suisse Securities (USA) LLC and its successors, or if that firm is unwilling or unable to serve as such, an independent investment and banking institution of national standing appointed by the Company.

“Reference Treasury Dealer” means:

• Credit Suisse Securities (USA) LLC and its successors; provided that, if Credit Suisse Securities (USA) LLC ceases to be a primary U.S. Government securities dealer in New York City (Primary Treasury Dealer), another Primary Treasury Dealer appointed by the Company; and

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• up to four other Primary Treasury Dealers selected by the Company.

“Reference Treasury Dealer Quotations” means, with respect to each Reference Treasury Dealer and any Redemption Date, the average, as determined by the Independent Investment Banker, of the bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted in writing to the Independent Investment Banker at 5:00 p.m., New York City time, on the third Business Day preceding such Redemption Date.

The Corporate Trustee shall be under no duty to inquire into, may conclusively presume the correctness of, and shall be fully protected in acting upon the calculation by the Independent Investment Banker of any Redemption Price of the Bonds.

B-8

INSTRUMENT OF ASSIGNMENT AND TRANSFER

FOR VALUE-RECEIVED the undersigned hereby sell(s), assign(s) and transfer(s) unto

Identifying Number of Assignee _________________________________________________

__________________________________________________________________________________

__________________________________________________________________________________

__________________________________________________________________________________

(Please print or typewrite name and address,

including zip code of Assignee)

the within Bond and all rights thereunder, hereby irrevocably constituting and appointing _____ attorney to transfer said Bond on the books of the Company, with full power of substitution in the premises.

Dated: ____________________________

___________________________________

Name:

NOTICE: The signature to this assignment must correspond with the name as written upon the first page of the within instrument in every particular, without alteration or enlargement or any change whatsoever.

__________________________

Signature Guarantee

SIGNATURE GUARANTEE

Signatures must be guaranteed by an “eligible guarantor institution” meeting the requirements of the Registrar, which requirements include membership or participation in the Security Transfer Agent Medallion Program (“STAMP”) or such other “signature guarantee program” as may be determined by the Registrar in addition to, or in substitution for, STAMP, all in accordance with the Securities Exchange Act of 1934, as amended.

B-9

SCHEDULE OF EXCHANGES OF INTERESTS IN THE GLOBAL BOND

The following exchanges of a part of this Global Bond for an interest in another Global Bond or for a Certificated Bond, or exchanges of a part of another Global Bond or Certificated Bond for an interest in this Global Bond, have been made:

Date of
Exchange Amount of
decrease in
Principal
Amount of this
Global Bond Amount of
increase in
Principal
Amount of this
Global Bond Principal
Amount of this
Global Bond
following such
decrease
(or increase) Signature of
authorized
officer of
Corporate
Trustee or Bond
Custodian

_________________________

This should be included only if the Bond is issued in global form.

B-10

EXHIBIT C

FORM OF CERTIFICATE OF TRANSFER

NorthWestern Corporation

125 S. Dakota Avenue

Sioux Falls, South Dakota 57104

The Bank of New York

101 Barclay Street

New York, New York 10286

Re: First Mortgage Bonds, 6.04% Series due 2016 (the “Bonds”)

Reference is hereby made to the Twenty-sixth Supplemental Indenture, dated as of September 1, 2006 (the "Indenture"), between NorthWestern Corporation, as issuer (the "Company"), and The Bank of New York and Ming Ryan, as trustees. Capitalized terms used but not defined herein shall have the meanings given to them in the Indenture.

______________________, (the "Transferor") owns and proposes to transfer the Bond[s] or interest in such Bonds[s] specified in Annex A hereto, in the principal amount of $ ______ in such Bonds[s] or interests (the "Transfer"), to_________________ (the "Transferee"), as further specified in Annex A hereto. In connection with the Transfer, the Transferor hereby certifies that:

[CHECK ALL THAT APPLY]

1.[ ] Check if Transferee will take delivery of a beneficial interest in the 144A Global Bond or a Certificated Bond Pursuant to Rule 144A. The Transfer is being effected pursuant to and in accordance with Rule 144A under the United States Securities Act of 1933, as amended (the "Securities Act"), and, accordingly, the Transferor hereby further certifies that the beneficial interest or Certificated Bond is being transferred to a Person that the Transferor reasonably believed and believes is purchasing the beneficial interest or Certificated Bond for its own account, or for one or more accounts with respect to which such Person exercises sole investment discretion, and such Person and each such account is a "qualified institutional buyer" within the meaning of Rule 144A in a transaction meeting the requirements of Rule 144A and such Transfer is in compliance with any applicable blue sky securities laws of any state of the United States. Upon consummation of the proposed Transfer in accordance with the terms of the Indenture, the transferred beneficial interest or Certificated Bond will be subject to the restrictions on transfer enumerated in the Private Placement Legend printed on the 144A Global Bond and/or the Certificated Bond and in the Indenture and the Securities Act.

2.[ ] Check If Transferee will take delivery of a beneficial interest in the Regulation S Global Bond or a Certificated Bond pursuant to Regulation S. The Transfer is being effected pursuant to and in accordance with Rule 903 or Rule 904 under the Securities Act and, accordingly, the Transferor hereby further certifies that (i) the Transfer is not being made to a person in the United States and (x) at the time the buy order was

C-1

originated, the Transferee was outside the United States or such Transferor and any Person acting on its behalf reasonably believed and believes that the Transferee was outside the United States or (y) the transaction was executed in, on or through the facilities of a designated offshore securities market and neither such Transferor nor any Person acting on its behalf knows that the transaction was prearranged with a buyer in the United States, (ii) no directed selling efforts have been made in contravention of the requirements of Rule 903(b) or Rule 904(b) of Regulation S under the Securities Act, (iii)-the transaction is not part of a plan or scheme to evade the registration requirements of the Securities Act and (iv) if the proposed transfer is being made prior to the expiration of the Restricted Period, the transfer is not being made to a U.S. Person or for the account or benefit of a U.S. Person (other than an Initial Purchaser). Upon consummation of the proposed transfer in accordance with the terms of the Indenture, the transferred beneficial interest or Certificated Bond will be subject to the restrictions on Transfer enumerated in the Private Placement Legend printed on the Regulation S Global Bond, and/or the Certificated Bond and in the Indenture and the Securities Act.

3.[ ] Check and complete if Transferee will take delivery of a beneficial interest in a Global Bond or a Certificated Bond pursuant to any provision of the Securities Act other than Rule 144A or Regulation S. The Transfer is being effected in compliance with the transfer restrictions applicable to beneficial interests in Restricted Global Bonds and Restricted Certificated Bonds and pursuant to and in accordance with the Securities Act and any applicable blue sky securities laws of any state of the United States, and accordingly the Transferor hereby further certifies that (check one):

[ ] such Transfer is being effected pursuant to and in accordance with Rule 144 under the Securities Act;

or

[ ] such Transfer is being effected to the Company or a subsidiary thereof;

or

[ ] such Transfer is being effected pursuant to an effective registration statement under the Securities Act and in compliance with the prospectus delivery requirements of the Securities Act.

4.[ ] Check if Transferee will take delivery of a beneficial interest in an Unrestricted Global Bond or an Unrestricted Certificated Bond.

(a) [ ] Check if Transfer is pursuant to Rule 144. (i) The Transfer is being effected pursuant to and in accordance with Rule 144 under the Securities Act and in compliance with the transfer restrictions contained in the Indenture and any applicable blue sky securities laws of any state of the United States and (ii) the restrictions on transfer contained in the Indenture

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and the Private Placement Legend are not required in order to maintain compliance with the Securities Act. Upon consummation of the proposed Transfer in accordance with the terms of the Indenture, the transferred beneficial interest or Certificated Bond will no longer be subject to the restrictions on transfer enumerated in the Private Placement Legend printed on the Restricted Global Bonds, on Restricted Certificated Bonds and in the Indenture.

(b) [ ] Check if Transfer is Pursuant to Regulation S. (i) The Transfer is being effected pursuant to and in accordance with Rule 903 or Rule 904 under the Securities Act and in compliance with the transfer restrictions contained in the Indenture and any applicable blue sky securities laws of any state of the United States and (ii) the restrictions on transfer contained in the Indenture and the Private Placement Legend are not required in order to maintain compliance with the Securities Act. Upon consummation of the proposed Transfer in accordance with the terms of the Indenture, the transferred beneficial interest or Certificated Bond will no longer be subject to the restrictions on transfer enumerated in the Private Placement Legend printed on the Restricted Global Bonds, on Restricted Certificated Bonds and in the Indenture.

(c) [ ] Check if Transfer is Pursuant to Other Exemption. (i) The Transfer is being effected pursuant to and in compliance with an exemption from the registration requirements of the Securities Act other than Rule 144, Rule 903 or Rule 904 and in compliance with the transfer restrictions contained in the Indenture and any applicable blue sky securities laws of any State of the United States and (ii) the restrictions on transfer contained in the Indenture and the Private Placement Legend are not required in order to maintain compliance with the Securities Act. Upon consummation of the proposed Transfer in accordance with the terms of the Indenture, the transferred beneficial interest or Certificated Bond will not be subject to the restrictions on transfer enumerated in the Private Placement Legend printed on the Restricted Global Bonds or Restricted Certificated Bonds and in the Indenture.

This certificate and the statements contained herein are made for the benefit of the Trustee and the Registrar and the benefit of the Company.

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                                      _______

[Insert Name of Transferor]

By:
	Name:
	Title:

Dated:

__________________________

Signature Guarantee

SIGNATURE GUARANTEE

Signatures must be guaranteed by an “eligible guarantor institution” meeting the requirements of the Registrar, which requirements include membership or participation in the Security Transfer Agent Medallion Program (“STAMP”) or such other “signature guarantee program” as may be determined by the Registrar in addition to, or in substitution for, STAMP, all in accordance with the Securities Exchange Act of 1934, as amended.

C-4

ANNEX A TO CERTIFICATE OF TRANSFER

1. The Transferor owns and proposes to transfer the following:

[CHECK ONE OF (a) OR (b)]

(1)
a beneficial interest in the:

[ ] 144A Global Bond (CUSIP ________), or

[ ] Regulation S Global Bond (CUSIP ________), or

	(2)	a Restricted Certificated Bond.
2.	After the Transfer the Transferee will hold:

[CHECK ONE]

(3)
a beneficial interest in the:

[ ] 144A Global Bond (CUSIP ______), or

[ ] Regulation S Global Bond (CUSIP ______), or

[ ] Unrestricted Global Bond (CUSIP ______), or

(4)	a Restricted Certificated Bond; or
(5)	an Unrestricted Certificated Bond,

in accordance with the terms of the Indenture.

C-5

EXHIBIT D

FORM OF CERTIFICATE OF EXCHANGE

NorthWestern Corporation

125 S. Dakota Avenue

Sioux Falls, South Dakota 57104

The Bank of New York

101 Barclay Street

New York, New York 10286

Re: First Mortgage Bonds, 6.04% Series due 2016 (the “Bonds”)

(CUSIP ______)

Reference is hereby made to the Twenty-sixth Supplemental Indenture, dated as of September 1, 2006 (the "Indenture"), between NorthWestern Corporation, as issuer (the "Company"), and The Bank of New York and Ming Ryan, as trustees. Capitalized terms used but not defined herein shall have the meanings given to them in the Indenture.

_______________________, (the "Owner") owns and proposes to exchange the Bond[s] or interest in such Bond[s] specified herein, in the principal amount of $__________ in such Bond[s] or interests (the "Exchange"). In connection with the Exchange, the Owner hereby certifies that:

1.Exchange of Restricted Certificated Bonds or Beneficial Interests in a Restricted Global Bonds for Unrestricted Certificated Bond or Beneficial Interests in an Unrestricted Global Bond

(a)[ ] Check if Exchange is from beneficial interest in a Restricted Global Bond to beneficial interest in an Unrestricted Global Bond. In connection with the Exchange of the Owner's beneficial interest in a Restricted Global Bond for a beneficial interest in an Unrestricted Global Bond in an equal principal amount, the Owner hereby certifies (i) the beneficial interest is being acquired for the Owner's own account without transfer, (ii) such Exchange has been effected in compliance with the transfer restrictions applicable to the Global Bonds and pursuant to and in accordance with the United States Securities Act of 1933, as amended (the "Securities Act"), (iii) the restrictions on transfer contained in the Indenture and the Private Placement Legend are not required in order to maintain compliance with the Securities Act and (iv) the beneficial interest in an Unrestricted Global Bond is being acquired in compliance with any applicable blue sky securities laws of any state of the United States.

(b)
[Intentionally omitted]

(c)[ ] Check if Exchange is from Restricted Certificated Bond to beneficial interest in an Unrestricted Global Bond. In connection with the Owner's Exchange of a

D-1

Restricted Certificated Bond for a beneficial interest in an Unrestricted Global Bond, the Owner hereby certifies (i) the beneficial interest is being acquired for the Owner's own account without transfer, (ii) such Exchange has been effected in compliance with the transfer restrictions applicable to Restricted Certificated Bonds and pursuant to and in accordance with the Securities Act, (iii) the restrictions on transfer contained in the Indenture and the Private Placement Legend are not required in order to maintain compliance with the Securities Act and (iv) the beneficial interest is being acquired in compliance with any applicable blue sky securities laws of any state of the United States.

(d)[ ] Check if Exchange is from Restricted Certificated Bond to Unrestricted Certificated Bond. In connection with the Owner's Exchange of a Restricted Certificated Bond for an Unrestricted Certificated Bond, the Owner hereby certifies (i) the Unrestricted Certificated Bond is being acquired for the Owner's own account without transfer, (ii) such Exchange has been effected in compliance with the transfer restrictions applicable to Restricted Certificated Bonds and pursuant to and in accordance with the Securities Act, (iii) the restrictions on transfer contained in the Indenture and the Private Placement Legend are not required in order to maintain compliance with the Securities Act and (iv) the Unrestricted Certificated Bond is being acquired in compliance with any applicable blue sky securities laws of any state of the United States.

2.Exchange of Restricted Certificated Bonds or Beneficial Interests in Restricted Global Bonds for Restricted Certificated Bonds or Beneficial Interests in Restricted Global Bonds

(a)
[Intentionally omitted]

(b) [ ] Check if Exchange is from Restricted Certificated Bond to beneficial interest in a Restricted Global Bond. In connection with the Exchange of the Owner's Restricted Certificated Bond for a beneficial interest in the [CHECK ONE] [ ] 144A Global Bond, [ ] Regulation S Global Bond with an equal principal amount, the Owner hereby certifies (i) the beneficial interest is being acquired for the Owner's own account without transfer and (ii) such Exchange has been effected in compliance with the transfer restrictions applicable to the Restricted Global Bonds and pursuant to and in accordance with the Securities Act, and in compliance with any applicable blue sky securities laws of any state of the United States. Upon consummation of the proposed Exchange in accordance with the terms of the Indenture, the beneficial interest issued will be subject to the restrictions on transfer enumerated in the Private Placement Legend printed on the relevant Restricted Global Bond and in the Indenture and the Securities Act.

This certificate and the statements contained herein are made for the benefit of the Trustee and the Registrar and the benefit of the Company.

[Insert Name of Transferor]

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By:

Name:

Title:

Dated:

__________________________

Signature Guarantee

SIGNATURE GUARANTEE

Signatures must be guaranteed by an “eligible guarantor institution” meeting the requirements of the Registrar, which requirements include membership or participation in the Security Transfer Agent Medallion Program (“STAMP”) or such other “signature guarantee program” as may be determined by the Registrar in addition to, or in substitution for, STAMP, all in accordance with the Securities Exchange Act of 1934, as amended.

D-3

EX-10

$150,000,000

NorthWestern Corporation

6.04% First Mortgage Bonds due 2016

PURCHASE AGREEMENT

September 6, 2006

CREDIT SUISSE SECURITIES (USA) LLC

DEUTSCHE BANK SECURITIES INC.,

As Representatives of the Several Purchasers,

c/o Credit Suisse Securities (USA) LLC,
	Eleven Madison Avenue,
	New York, N.Y. 10010-3629

Dear Sirs:

1. Introductory. NorthWestern Corporation, a Delaware corporation (the “Company”), proposes, subject to the terms and conditions stated herein, to issue and sell to the several initial purchasers named in Schedule A hereto (the “Purchasers”) U.S. $150,000,000 principal amount of its 6.04% First Mortgage Bonds due 2016 (“Offered Securities”). The United States Securities Act of 1933, as amended, is herein referred to as the “Securities Act”.

The Offered Securities are to be issued under the Mortgage and Deed of Trust, dated as of October 1, 1945, of the Company (as successor to NorthWestern Energy, L.L.C., in turn successor to The Montana Power Company) to The Bank of New York (as successor to Guaranty Trust Company of New York), as corporate trustee (the “Trustee”), and Ming Ryan (as indirect successor to Arthur E. Burke), as individual trustee, as amended and supplemented by various instruments including the supplemental indenture, to be dated as of the Closing Date (as defined herein) (the “Supplemental Indenture”), establishing the terms of the Offered Securities, such Mortgage and Deed of Trust, as so amended and supplemented, being hereinafter called the “Mortgage”.

The holders of the Offered Securities will be entitled to the benefits of a Registration Rights Agreement, to be dated as of the Closing Date, among the Company and the Purchasers (the “Registration Rights Agreement”), pursuant to which the Company will agree to file a registration statement with the Securities and Exchange Commission (the “Commission”) registering an exchange offer or the resale of the Offered Securities under the Securities Act.

The Company hereby agrees with the several Purchasers as follows:

2. Representations and Warranties of the Company. The Company represents and warrants to, and agrees with, the several Purchasers that:

(a)A preliminary offering circular (the “Preliminary Offering Circular”) dated September 5, 2006 relating to the Offered Securities and a final offering circular (the “Final Offering Circular”) disclosing the offering price and other terms of the Offered Securities, dated as of the date of this Agreement (even if finalized and issued subsequent to the date of this Agreement) have been or will be prepared by the Company. “General Disclosure Package” means the Preliminary Offering Circular, together with any Issuer Free Writing Communication (as hereinafter defined) existing at the Applicable Time (as hereinafter defined) and the information which is intended for general distribution to prospective investors, as evidenced by it being specified in Schedule C to this Agreement (including the term sheet listing the final terms of the Offered Securities and their offering, included in Schedule C to this Agreement, which is referred to as the “Terms Communication”). “Applicable Time” means 3:15 pm (New York City time) on the date of this Agreement

or such other time as may be agreed upon by the parties hereto. As of the date of this Agreement and at all times subsequent thereto up to the Closing Date, the Final Offering Circular does not and will not include any untrue statement of a material fact or omit to state any material fact necessary in order to make the statements therein, in light of the circumstances under which they were made, not misleading. At the Applicable Time and at all times subsequent thereto up to the Closing Date, neither (i) the General Disclosure Package, nor (ii) any individual Supplemental Marketing Material (as hereinafter defined), when considered together with the General Disclosure Package, included or will include any untrue statement of a material fact or omitted or will omit to state any material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading. The preceding two sentences do not apply to statements in or omissions from the Preliminary or Final Offering Circular, the General Disclosure Package or any Supplemental Marketing Material based upon written information furnished to the Company by any Purchaser through Credit Suisse Securities (USA) LLC or Deutsche Bank Securities Inc. (collectively, the “Representatives”) specifically for use therein, it being understood and agreed that the only such information is that described as such in Section 8(b) hereof. On the date of this Agreement, the Company’s Annual Report on Form 10-K most recently filed with the Commission and all subsequent reports (collectively, the “Exchange Act Reports”) which have been filed by the Company with the Commission or sent to holders pursuant to the Securities Exchange Act of 1934, as amended (the “Exchange Act”) do not include any untrue statement of a material fact or omit to state any material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading. Such documents, when they were filed with the Commission, conformed in all material respects to the requirements of the Exchange Act and the rules and regulations of the Commission thereunder.

“Free Writing Communication” means a written communication (as such term is defined in Rule 405 under the Securities Act) that constitutes an offer to sell or a solicitation of an offer to buy the Offered Securities and is made by means other than the Preliminary Offering Circular or the Final Offering Circular. “Issuer Free Writing Communication” means a Free Writing Communication prepared by or on behalf of the Company, used or referred to by the Company or containing a description of the final terms of the Offered Securities or of their offering, in the form retained in the Company’s records. “Supplemental Marketing Material” means any Issuer Free Writing Communication other than any Issuer Free Writing Communication specified in Schedule C to this Agreement.

(b)The Company has been duly incorporated and is an existing corporation in good standing under the laws of the State of Delaware, with power and authority (corporate and other) to own its properties and conduct its business as described in the General Disclosure Package and the Final Offering Circular; and the Company is duly qualified to do business as a foreign corporation in good standing in all other jurisdictions in which its ownership or lease of property or the conduct of its business requires such qualification, except where the failure so to qualify or to be in good standing would not, individually or in the aggregate, result in a material adverse effect on the condition (financial or other), business, properties or results of operations of the Company and its subsidiaries taken as a whole (“Material Adverse Effect”).

(c)The Company has no “significant subsidiaries” (as such term is defined in Rule 1-02 of Regulation S-X).

(d)The Mortgage has been duly authorized by the Company and, when the Supplemental Indenture has been duly executed and delivered by the Company and assuming the due authorization, execution and delivery of the Supplemental Indenture by the Trustee, will constitute a valid and binding agreement of the Company, enforceable against the Company in accordance with its terms, except to the extent that enforcement of the lien thereof may be limited by the effect of certain laws of the jurisdictions in which the physical properties covered thereby are located upon the remedies provided in the Mortgage, which limitations, however, do not make the remedies afforded inadequate for the realization of the benefits of the security provided by the Mortgage, and except as enforceability of such lien may be limited by bankruptcy, insolvency, reorganization, moratorium or other similar laws affecting the enforcement of creditors’ rights, and except that the availability of the remedy of specific performance or injunctive relief is subject to the discretion of the court before which any proceeding thereof may be brought).

2

(e)The Offered Securities have been duly authorized by the Company and, when delivered and paid for pursuant to this Agreement on the Closing Date, will be duly executed, authenticated, issued and delivered, and will constitute valid and binding obligations of the Company, entitled to the benefits of the security provided by the lien of the Mortgage (except to the extent that enforceability of such lien may be limited by the effect of certain laws of the jurisdictions in which the physical properties covered thereby are located upon the remedies provided in the Mortgage, which limitations, however, do not make the remedies afforded inadequate for the realization of the benefits of the security provided by the Mortgage, and except as enforceability of such lien may be limited by bankruptcy, insolvency, reorganization, moratorium or other similar laws affecting the enforcement of creditors’ rights, and except that the availability of the remedy of specific performance or injunctive relief is subject to the discretion of the court before which any proceeding thereof may be brought).

(f)The Mortgage (excluding the Supplemental Indenture) constitutes, and the Mortgage, when the Supplemental Indenture shall have been duly filed for recording and recorded, will constitute, a valid and enforceable first mortgage lien for the equal and proportionate security of the first mortgage bonds issued or to be issued thereunder, upon substantially all of the physical properties and franchises of the Company which are specifically described therein as subject to the lien thereof and which are used or useful in the conduct of the Company’s utility business in Montana and Wyoming, free from all prior liens, charges or encumbrances (other than Excepted Encumbrances (as defined in the Mortgage); and other than, in the case of property acquired after the date of the original execution and delivery of the Mortgage, vendors’ liens, purchase money mortgages and any other liens thereon at the time of acquisition thereof) (except to the extent that enforceability of such lien may be limited by the effect of certain laws of the jurisdictions in which the physical properties covered thereby are located upon the remedies provided in the Mortgage, which limitations, however, do not make the remedies afforded inadequate for the realization of the benefits of the security provided by the Mortgage, and except as enforceability of such lien may be limited by bankruptcy, insolvency, reorganization, moratorium or other similar laws affecting the enforcement of creditors’ rights, and except that the availability of the remedy of specific performance or injunctive relief is subject to the discretion of the court before which any proceeding therefor may be brought); and the after-acquired property clause in the Mortgage subjects to the lien thereof all after-acquired utility property of the Company’s utility business in Montana and Wyoming as provided therein (except such thereof as is expressly excepted from the lien of the Mortgage).

(g)The Mortgage (excluding the Supplemental Indenture and including any necessary related financing statements) has been filed and recorded wherever and to the extent necessary to perfect the lien thereof upon the properties now owned by the Company and intended to be subject thereto; all fees or taxes in connection therewith have been paid and no other filing or recordation is presently necessary in order to perfect the lien of the Mortgage on such properties.

(h)No filing or recording of the Supplemental Indenture is necessary to perfect the lien of the Mortgage upon the properties now owned by the Company and intended to be subject thereto or to extend such lien for the benefit of the Offered Securities to be issued thereunder; no re-recording or refiling of the Mortgage or any other instruments or documents (except for periodic filings which extend the effectiveness of financing statements) is required to preserve and protect the lien of the Mortgage; and under the present laws of the states in which the property intended to be subject to the lien of the Mortgage is located, no further supplemental indentures or other instruments or documents are required to be executed, filed and/or recorded to extend the lien of the Mortgage to after-acquired property; however, the Company is required by the terms of the Mortgage to promptly record and file the Supplemental Indenture.

(i)The Company has good and marketable title to all properties owned by it which are subject to the Mortgage, subject only (a) to the lien of the Mortgage, (b) to Excepted Encumbrances (as defined in the Mortgage) and (c) to minor exceptions and defects which do not, in the aggregate, materially interfere with the use by the Company of such properties for the purposes for which they are held, materially detract from the value of said properties or in any material way impair the security afforded by the Mortgage; and such properties constitute and comprise substantially all of the utility properties directly owned by the Company in the States of Montana and Wyoming.

3

(j)The descriptions of the Offered Securities, the Mortgage and the Registration Rights Agreement in the General Disclosure Package and the Final Offering Circular are accurate in all material respects.

(k) Except as disclosed in the General Disclosure Package and the Final Offering Circular, there are no contracts, agreements or understandings between the Company and any person that would give rise to a valid claim against the Company or any Purchaser for a brokerage commission, finder’s fee or other like payment.

(l)No consent, approval, authorization, or order of, or filing with, any governmental agency or body or any court is required for the consummation of the transactions contemplated by this Agreement, the Registration Rights Agreement or the Mortgage in connection with the issuance and sale of the Offered Securities by the Company except for filings with or the orders of (i) the Commission declaring the Exchange Offer Registration Statement or, if required, the Shelf Registration Statement (each as defined in the Registration Rights Agreement) effective, (ii) the Montana Public Service Commission (“MPSC”), (iii) the Federal Energy Regulatory Commission (“FERC”), or as may otherwise be required under state securities laws or as have already been obtained.

(m)The execution, delivery (or assumption) and performance of this Agreement, the Mortgage and the Registration Rights Agreement and the issuance and sale of the Offered Securities and compliance with the terms and provisions thereof will not result in a breach or violation of any of the terms and provisions of, or constitute a default under, (i) any statute, any rule, regulation or order of any governmental agency or body or any court, domestic or foreign, having jurisdiction over the Company or any subsidiary of the Company or any of their properties, or (ii) any agreement or instrument to which the Company or any such subsidiary is a party or by which the Company or any such subsidiary is bound or to which any of the properties of the Company or any such subsidiary is subject, or (iii) the charter or by-laws of the Company or any such subsidiary, except, in the case of (i) and (ii) above, for breaches or violations that would not, individually or in the aggregate, have a Material Adverse Effect, and the Company has full power and authority to authorize, issue and sell the Offered Securities as contemplated by this Agreement.

(n)The Company has all the requisite corporate power and authority to execute, deliver and perform its obligations under this Agreement and the transactions contemplated hereby. This Agreement has been duly authorized, executed and delivered by the Company.

(o)On the date hereof, the authorized, issued and outstanding capital stock of the Company is as set forth in the General Disclosure Package and the Final Offering Circular in the column entitled “Actual” under the caption “Capitalization” (except for subsequent issuances, if any, pursuant to reservations, agreements or employee benefit plans referred to in the General Disclosure Package and the Final Offering Circular). The shares of issued and outstanding capital stock of the Company on the date hereof and on the Closing Date have been, and will be, duly authorized and validly issued and are, and will be, fully paid and non-assessable; none of the outstanding shares of capital stock of the Company on the date hereof and on the Closing Date was, or will have been, issued in violation of the preemptive or other similar rights of any securityholder of the Company.

(p)The Company and its subsidiaries possess adequate certificates, licenses, approvals, franchises, authorizations or permits (collectively, “Governmental Licenses”) issued by the appropriate federal, state, local or foreign regulatory agencies or bodies necessary to conduct the business now operated by them, except where the failure to have such Governmental Licenses would not, individually or in the aggregate, have a Material Adverse Effect; and have not received any notice of proceedings relating to the revocation or modification of any such Governmental Licenses that, if determined adversely to the Company or any of its subsidiaries, would individually or in the aggregate result in a Material Adverse Effect.

(q)Except as otherwise disclosed in the General Disclosure Package and the Final Offering Circular, no labor dispute with the employees of the Company or any subsidiary exists or, to the knowledge of the Company, is imminent that would have a Material Adverse Effect.

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(r)The Company and its subsidiaries own, possess or can acquire on reasonable terms, adequate trademarks, trade names and other rights to inventions, know-how, patents, copyrights, confidential information and other intellectual property (collectively, “intellectual property rights”) necessary to conduct the business now operated by them, or presently employed by them except in cases in which the failure to own or possess such intellectual property rights would not, individually or in the aggregate, have a Material Adverse Effect, and have not received any notice of infringement of or conflict with asserted rights of others with respect to any intellectual property rights that, if determined adversely to the Company or any of its subsidiaries, would individually or in the aggregate have a Material Adverse Effect.

(s)Except as disclosed in the General Disclosure Package and the Final Offering Circular or would not, singly or in the aggregate, result in a Material Adverse Effect, (A) neither the Company nor any of its subsidiaries is in violation of any federal, state, local or foreign statute, any rule, regulation, decision or order of any governmental agency or body or any court, domestic or foreign, relating to the use, disposal or release of hazardous or toxic substances or relating to the protection or restoration of the environment or human exposure to hazardous or toxic substances (collectively, “environmental laws”); and (B) to the knowledge of the Company there are no pending or threatened administrative, regulatory or judicial actions, suits, demands, demand letters, claims, liens, notices of noncompliance or violation, investigation or proceedings relating to any environmental laws against the Company or any of its subsidiaries.

(t)Except as disclosed in the General Disclosure Package and the Final Offering Circular, there are no pending actions, suits or proceedings against or affecting the Company, any of its subsidiaries or any of their respective properties that, if determined adversely to the Company or any of its subsidiaries, would individually or in the aggregate have a Material Adverse Effect, or would materially and adversely affect the ability of the Company to perform its obligations under the Mortgage, this Agreement or the Registration Rights Agreement, to issue and deliver the Offered Securities; and to the knowledge of the Company no such actions, suits or proceedings have been threatened.

(u)The FERC has issued an appropriate order or orders with respect to the issuance and sale of the Offered Securities in accordance with this Agreement (the “FERC Order”); the FERC Order is in full force and effect and the issuance of the Offered Securities pursuant to this Agreement is in conformity with the terms of the FERC Order.

(v)The MPSC has issued an appropriate order or orders with respect to the issuance and delivery of the Offered Securities in accordance with this Agreement and the Mortgage (the “MPSC Order”); the MPSC Order is in full force and effect and the issuance and delivery of the Offered Securities pursuant to this Agreement is in conformity with the terms of the MPSC Order.

(w)Deloitte & Touche LLP, who audited the financial statements of the Company of the Company incorporated by reference in the General Disclosure Package and the Final Offering Circular, is an independent registered public accounting firm with respect to the Company within the meaning of the Securities Act and the applicable published rules and regulations thereunder (“Rules and Regulations”)

(x)The financial statements incorporated by reference in the General Disclosure Package and the Final Offering Circular present fairly in all material respects the financial position of the Company and its consolidated subsidiaries as of the dates shown and their results of operations and cash flows for the periods shown, and, except as otherwise disclosed in the General Disclosure Package and the Final Offering Circular, such financial statements have been prepared in conformity with the generally accepted accounting principles in the United States applied on a consistent basis (except that the unaudited financial statements may be subject to normal year-end adjustments) throughout the periods involved; and the assumptions used in preparing the pro forma financial statements included in the General Disclosure Package and the Final Offering Circular provide a reasonable basis for presenting the significant effects directly attributable to the transactions or events described therein, the related pro forma adjustments give appropriate effect to those assumptions and the pro forma columns therein reflect the proper application of those adjustments to the corresponding historical financial statement amounts.

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(y)Since the date of the latest audited financial statements incorporated by reference in the General Disclosure Package and the Final Offering Circular, except as disclosed in the General Disclosure Package and the Final Offering Circular, there has been no material adverse change, nor any development or event involving a prospective material adverse change, in the condition (financial or other), business, properties or results of operations of the Company and its subsidiaries taken as a whole, and, except as disclosed in or contemplated by the General Disclosure Package and the Final Offering Circular, there has been no dividend or distribution of any kind declared, paid or made by the Company on any class of its capital stock.

(z)The Company is subject to the reporting requirements of either Section 13 or Section 15(d) of the Securities Exchange Act of 1934 and files reports with the Commission on the Electronic Data Gathering, Analysis, and Retrieval (EDGAR) system.

(aa)The Company is not an open-end investment company, unit investment trust or face-amount certificate company that is or is required to be registered under Section 8 of the United States Investment Company Act of 1940, as amended (the “Investment Company Act”); and the Company is not and, after giving effect to the offering and sale of the Offered Securities and the application of the proceeds therefrom as described in the General Disclosure Package and the Final Offering Circular, will not be required to be so registered under the Investment Company Act.

(bb)Any certificate signed by any officer of the Company or any of its subsidiaries delivered to the Purchasers or to counsel for the Purchasers in connection with this Agreement shall be deemed a representation and warranty by the Company, to the Purchasers as to the matters covered thereby.

(cc)No securities of the same class (within the meaning of Rule 144A(d)(3) under the Securities Act) as the Offered Securities are listed on any national securities exchange registered under Section 6 of the Exchange Act or quoted in a U.S. automated inter-dealer quotation system.

(dd)Subject to the accuracy of the representations and warranties and the due performance of the agreements of the Purchasers in Section 4 of this Agreement (including, without limitation, the transfer restrictions referred to therein), the offer, sale and delivery of the Offered Securities to the Purchasers in the manner contemplated by this Agreement and the General Disclosure Package and the Final Offering Circular and the initial resale of the Offered Securities by the Purchasers in the manner contemplated in the Offering Document and this Agreement, do not require registration under the Securities Act, and the Supplemental Indenture does not require qualification under the United States Trust Indenture Act of 1939, as amended (the “Trust Indenture Act”).

(ee)Neither the Company, nor any of its affiliates, nor any person acting on its or their behalf (i) has, within the six-month period prior to the date hereof, offered or sold in the United States or to any U.S. person (as such terms are defined in Regulation S under the Securities Act) the Offered Securities or any security of the same class or series as the Offered Securities or (ii) has offered or will offer or sell the Offered Securities (A) in the United States by means of any form of general solicitation or general advertising within the meaning of Rule 502(c) under the Securities Act or (B) with respect to any such securities sold in reliance on Rule 903 of Regulation S (“Regulation S”) under the Securities Act, by means of any directed selling efforts within the meaning of Rule 902(c) of Regulation S. The Company, its affiliates and any person acting on its or their behalf have complied and will comply with the offering restrictions requirement of Regulation S in connection with the offering of the Offered Securities outside the United States. The Company has not entered and will not enter into any contractual arrangement with respect to the distribution of the Offered Securities except for this Agreement.

(ff)The entities listed on Schedule B hereto are the only subsidiaries (within the meaning of Rule 405 under the Securities Act), direct or indirect, of the Company.

(gg)The Exchange Securities have been duly authorized by the Company, and when executed, authenticated, issued and delivered in the manner provided for in the Mortgage and the Registration Rights Agreement, the Exchange Securities will constitute valid and binding obligations of the Company entitled to

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the benefits of the Mortgage (except to the extent that enforceability of such lien may be limited by the effect of certain laws of the jurisdictions in which the physical properties covered thereby are located upon the remedies provided in the Mortgage, which limitations, however, do not make the remedies afforded inadequate for the realization of the benefits of the security provided by the Mortgage, and except as enforceability of such lien may be limited by bankruptcy, insolvency, reorganization, moratorium or other similar laws affecting the enforcement of creditors’ rights, and except that the availability of the remedy of specific performance or injunctive relief is subject to the discretion of the court before which any proceeding thereof may be brought).

(hh)The Registration Rights Agreement has been duly authorized by the Company and when the Registration Rights Agreement has been duly executed and delivered by the Company (assuming the due authorization, execution and delivery by the Purchasers), the Registration Rights Agreement will be a valid and binding obligation of the Company, enforceable against the Company in accordance with its terms, except as enforcement thereof may be limited by bankruptcy, insolvency (including, without limitation, all laws relating to fraudulent transfers), reorganization, moratorium or similar laws affecting enforcement of creditors’ rights generally and except as enforcement thereof is subject to general principles of equity (regardless of whether enforcement is considered in a proceeding in equity or at law) or an implied covenant of good faith and fair dealing, and except that rights to indemnification thereunder may be limited by federal or state securities laws or public policy thereto.

(ii)Neither the Company nor any of its subsidiaries is in violation of its respective charter or by-laws or other governance documents or in default in the performance of any obligation, agreement, covenant or condition contained in any indenture, loan agreement, mortgage, lease or other agreement or instrument to which the Company or any of its subsidiaries is a party or by which the Company or any of its subsidiaries or their respective property is bound, which, individually or in the aggregate, would have a Material Adverse Effect.

(jj)There are no contracts or agreements between the Company and any person granting such person the right to require the Company to file a registration statement under the Securities Act with respect to any securities of the Company or to require the Company to include such securities with the Exchange Securities registered pursuant to any Exchange Offer Registration Statement.

(kk)Neither the Company nor any of its subsidiaries nor any agent thereof acting on the behalf of them has taken, and none of them will take, any action that might cause this Agreement or the issuance or sale of the Offered Securities to violate Regulation T, Regulation U or Regulation X of the Board of Governors of the Federal Reserve System.

(ll)No “nationally recognized statistical rating organization” as such term is defined for purposes of Rule 436(g)(2) under the Securities Act (i) has imposed (or has informed the Company that it is considering imposing) any condition (financial or otherwise) on the Company in order for the Company to maintain a rating of at least as high as any rating of the Offered Securities assigned to the Company as of the date hereof, or (ii) has indicated to the Company that it is considering (a) the downgrading, suspension, or withdrawal of, or any review for a possible downgrading in any rating so assigned or (b) any negative change in the outlook for any rating of the Offered Securities.

(mm)The sale of the Offered Securities pursuant to Regulation S is not part of a plan or scheme to evade the registration provisions of the Securities Act.

(nn)The Company maintains and will maintain “disclosure controls and procedures” (as defined in Rules 13a-15 and 15d-15(e) of the Exchange Act) reasonably designed to ensure that information required to be disclosed by the Company in the reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported in accordance with the Exchange Act and the rules and regulations thereunder. The Company has carried out and will carry out evaluations, under the supervision and with the participation of the Company’s principal executive and principal financial officers, of the effectiveness of the Company’s disclosure controls and procedures in accordance with Rule 13a-15 of the Exchange Act.

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3. Purchase, Sale and Delivery of Offered Securities. On the basis of the representations, warranties and agreements herein contained, but subject to the terms and conditions herein set forth, the Company agrees to sell to each Purchaser, and each Purchaser agrees, severally and not jointly, to purchase from the Company, the principal amount of Offered Securities set forth in Schedule A to this Agreement opposite the name of such Purchaser at the price set forth in Schedule A to this Agreement.

The Company will deliver against payment of the purchase price the Offered Securities in the form of one or more permanent global securities in definitive form (the “Global Securities”) deposited with the Trustee as custodian for The Depository Trust Company (“DTC”) and registered in the name of Cede & Co., as nominee for DTC. Interests in any permanent Global Securities will be held only in book-entry form through DTC, except in the limited circumstances described in the General Disclosure Package and the Final Offering Circular. Payment for the Offered Securities shall be made by the Purchasers in Federal (same day) funds by official check or checks or wire transfer to an account at a bank acceptable to the Representatives drawn to the order of the Company at the office of Dewey Ballantine LLP at 1301 Avenue of the Americas, New York, New York at 10:00 A.M. (New York time), on September 13, 2006, or at such other time not later than seven full business days thereafter as the Representatives and the Company determine, such time being herein referred to as the “Closing Date”, against delivery to the Trustee as custodian for DTC of the Global Securities representing all of the Securities. The Global Securities will be made available for checking at the above office of Dewey Ballantine LLP, at least 24 hours prior to the Closing Date.

4. Representations by Purchasers; Resale by Purchasers.  (a)   Each Purchaser severally represents and warrants to the Company that it is an “accredited investor” within the meaning of Regulation D under the Securities Act.

(a) Each Purchaser severally acknowledges that the Offered Securities have not been registered under the Securities Act and may not be offered or sold within the United States or to, or for the account or benefit of, U.S. persons except in accordance with Regulation S or pursuant to an exemption from the registration requirements of the Securities Act. Each Purchaser severally represents and agrees that it has offered and sold the Offered Securities, and will offer and sell the Offered Securities only in accordance with Rule 903 or Rule 144A under the Securities Act (“Rule 144A”). Accordingly, neither such Purchaser nor its affiliates, nor any persons acting on its or their behalf, have engaged or will engage in any directed selling efforts with respect to the Offered Securities, and such Purchaser, its affiliates and all persons acting on its or their behalf have complied and will comply with the offering restrictions requirement of Regulation S and Rule 144A.

(b) Each Purchaser severally agrees that it and each of its affiliates has not entered and will not enter into any contractual arrangement with respect to the distribution of the Offered Securities except for any such arrangements with the other Purchasers or affiliates of the other Purchasers or with the prior written consent of the Company.

(c) Each Purchaser severally agrees that it and each of its affiliates will not offer or sell the Offered Securities in the United States by means of any form of general solicitation or general advertising within the meaning of Rule 502(c) under the Securities Act, including, but not limited to (i) any advertisement, article, notice or other communication published in any newspaper, magazine or similar media or broadcast over television or radio, or (ii) any seminar or meeting whose attendees have been invited by any general solicitation or general advertising. Each Purchaser severally agrees, with respect to resales made in reliance on Rule 144A of any of the Offered Securities, to deliver either with the confirmation of such resale or otherwise prior to settlement of such resale a notice to the effect that the resale of such Offered Securities has been made in reliance upon the exemption from the registration requirements of the Securities Act provided by Rule 144A.

(d) Each of the Purchasers severally represents and agrees that (i) it has not offered or sold and prior to the expiry of a period of six months from the Closing Date, will not offer or sell any Offered Securities to persons in the United Kingdom except to persons whose ordinary activities involve them in acquiring, holding, managing or disposing of investments (as principal or agent) for the purposes of their businesses or otherwise in circumstances which have not resulted and will not result in an offer to the public in the United Kingdom within the meaning of the Public Offers of Securities Regulations 1995; (ii) it has only

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communicated or caused to be communicated and will only communicate or cause to be communicated any invitation or inducement to engage in investment activity (within the meaning of section 21 of the Financial Services and Markets Act 2000 (the “FSMA”)) received by it in connection with the issue or sale of any Offered Securities in circumstances in which section 21(1) of the FSMA does not apply to the Issuer; and (iii) it has complied and will comply with all applicable provisions of the FSMA with respect to anything done by it in relation to the Offered Securities in, from or otherwise involving the United Kingdom

5. Certain Agreements of the Company. The Company agrees with the several Purchasers that:

(a) The Company will advise the Representatives promptly of any proposal to amend or supplement the Preliminary or Final Offering Circular and will not effect such amendment or supplementation without the Representatives’ consent, which consent shall not be unreasonably withheld or delayed. If, at any time prior to the completion of the initial resale of the Offered Securities by the Purchasers, there occurs an event or development as a result of which any document included in the Preliminary or Final Offering Circular, the General Disclosure Package or any Supplemental Marketing Material included or would include an untrue statement of a material fact or omitted or would omit to state any material fact necessary in order to make the statements therein, in the light of the circumstances prevailing at such time, not misleading, the Company promptly will notify the Representatives of such event and promptly will prepare, at its own expense, an amendment or supplement which will correct such statement or omission. Neither the Representatives’ consent to, nor the Purchasers’ delivery to offerees or investors of, any such amendment or supplement shall constitute a waiver of any of the conditions set forth in Section 7.

(b) The Company will furnish to the Representatives copies of the Preliminary Offering Circular, each other document comprising a part of the General Disclosure Package, the Final Offering Circular, all amendments and supplements to such documents and each item of Supplemental Marketing Material, in each case as soon as available and in such quantities as the Representatives reasonably request. At any time when the Company is not subject to Section 13 or 15(d) of the Exchange Act, the Company will promptly furnish or cause to be furnished to the Representatives (and, upon request, to each of the other Purchasers) and, upon request of holders and prospective purchasers of the Offered Securities, to such holders and purchasers, copies of the information required to be delivered to holders and prospective purchasers of the Offered Securities pursuant to Rule 144A(d)(4) under the Securities Act (or any successor provision thereto) in order to permit compliance with Rule 144A in connection with resales by such holders of the Offered Securities. The Company will pay the expenses of printing and distributing to the Purchasers all such documents.

(c) The Company will arrange for the qualification of the Offered Securities for sale and the determination of their eligibility for investment under the laws of such jurisdictions in the United States and Canada as the Representatives reasonably designate and will continue such qualifications in effect so long as required for the initial resale of the Offered Securities by the Purchasers, provided that the Company will not be required to qualify as a foreign corporation or to file a general consent to service of process in any such state or subject itself to taxation in respect of doing business.

(d) During the period of two years after the Closing Date, the Company will, upon request, furnish to the Representatives, each of the other Purchasers and any holder of Offered Securities a copy of the restrictions on transfer applicable to the Offered Securities.

(e) During the period of two years after the Closing Date, the Company will not, and will not permit any of its affiliates (as defined in Rule 144 under the Securities Act) to, resell any of the Offered Securities that have been reacquired by any of them.

(f) During the shorter of (i) the period of two years after the Closing Date and (ii) the period from the Closing Date until the date upon which the transfer restrictions applicable to the Offered Securities shall no longer apply, the Company will not be or become, an open-end investment company, unit investment trust or face-amount certificate company that is or is required to be registered under Section 8 of the Investment Company Act.

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(g) The Company will pay all expenses incidental to the performance of its obligations under this Agreement, the Mortgage and the Registration Rights Agreement, including (i) the fees and expenses of the Trustee and its professional advisers; (ii) all expenses in connection with the execution, issue, authentication, packaging and initial delivery of the Offered Securities and, as applicable, the Exchange Securities (as defined in the Registration Rights Agreement), the preparation and printing of this Agreement, the Registration Rights Agreement, the Offered Securities, the Mortgage, the Preliminary Offering Circular, any other documents comprising any part of the General Disclosure Package, the Final Offering Circular, all amendments and supplements thereto, each item of Supplemental Marketing Material and any other document relating to the issuance, offer, sale and delivery of the Offered Securities and as applicable, the Exchange Securities; (iii) the cost of any advertising approved by the Company in connection with the issue of the Offered Securities; (iv) any expenses (including reasonable fees and disbursements of counsel for the Purchasers) incurred in connection with qualification of the Offered Securities or the Exchange Securities for sale under the laws of such jurisdictions in the United States and Canada as the Representatives reasonably designate and the printing of memoranda relating thereto; (v) any fees charged by investment rating agencies for the rating of the Offered Securities or the Exchange Securities; and (vi) the expenses incurred in distributing the Preliminary Offering Circular, any other documents comprising any part of the General Disclosure Package, the Final Offering Circular (including any amendments and supplements thereto) and any Supplemental Marketing Material to the Purchasers.

(h) In connection with the offering, until the Representatives shall have notified the Company and the other Purchasers of the completion of the initial resale of the Offered Securities, neither the Company nor any of its affiliates has or will, either alone or with one or more other persons, bid for or purchase for any account in which it or any of its affiliates has a beneficial interest any Offered Securities or attempt to induce any person to purchase any Offered Securities; and neither it nor any of its affiliates will make bids or purchases for the purpose of creating actual, or apparent, active trading in, or of raising the price of, the Offered Securities.

(i) The Company will not offer, sell, contract to sell, pledge or otherwise dispose of, directly or indirectly, or file with the Commission a registration statement under the Securities Act relating to, debt securities issued or guaranteed by the Company and having a maturity of more than one year from the date of issue, or publicly disclose the intention to make any such offer, sale, pledge, disposition or filing, without the prior written consent of the Representatives for a period beginning at the date of this Agreement and ending on the Closing Date. The Company will not at any time offer, sell, contract to sell, pledge or otherwise dispose of, directly or indirectly, any securities under circumstances where such offer, sale, pledge, contract or disposition would cause the exemption afforded by Section 4(2) of the Securities Act or the safe harbor of Regulation S thereunder to cease to be applicable to the offer and sale of the Offered Securities.

6. Free Writing Communications. (a) The Company represents and agrees that, unless it obtains the prior consent of the Representatives, and each Purchaser represents and agrees that, unless it obtains the prior consent of the Company and the Representatives, it has not made and will not make any offer relating to the Offered Securities that would constitute an Issuer Free Writing Communication.

(b) The Company consents to the use by a Purchaser of a Free Writing Communication that (i) contains only (A) information describing the preliminary terms of the Offered Securities or their offering or (B) information that describes the final terms of the Offered Securities or their offering and that is included in the Terms Communication or is included in or is subsequently included in the Final Offering Circular or (ii) does not contain any material information about the Company or its securities that was provided by or on behalf of the Company, it being understood and agreed that any such Free Writing Communication referred to in clause (i) or (ii) shall not be an Issuer Free Writing Communication for purposes of this Agreement.

7. Conditions of the Obligations of the Purchasers.  The obligations of the several Purchasers to purchase and pay for the Offered Securities will be subject to the accuracy of the representations and warranties on the part of the Company herein, to the accuracy of the statements of officers of the Company made pursuant to the provisions hereof, to the performance by the Company of its obligations hereunder and to the following additional conditions precedent:

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(a)The Purchasers shall have received a letter, dated the date of this Agreement, of Deloitte & Touche LLP confirming that they are an independent registered public accounting firm within the meaning of the Securities Act and the Rules and Regulations and to the effect that:

(i) in their opinion the financial statements examined by them and incorporated by reference in the Preliminary and Final Offering Circular comply as to form in all material respects with the applicable accounting requirements of the Securities Act and the related published Rules and Regulations that would apply to the Preliminary or Final Offering Circular if it were a prospectus included in a registration statement filed under the Securities Act;

(ii) they have performed the procedures specified by the standards of the Public Company Accounting Oversight Board (United States) for a review of interim financial information as described in PCAOB Interim Standard AU 722, Interim Financial Information, on the unaudited financial statements incorporated by reference in the Offering Document;

(iii) on the basis of the review referred to in clause (ii) above, a reading of the latest available interim financial statements of the Company, inquiries of officials of the Company who have responsibility for financial and accounting matters and other specified procedures, nothing came to their attention that caused them to believe that:

(A) the unaudited financial statements incorporated by reference in the Preliminary and Final Offering Circular do not comply as to form in all material respects with the applicable accounting requirements of the Securities Act and the related published Rules and Regulations or any material modifications should be made to such unaudited financial statements for them to be in conformity with accounting principles generally accepted in the United States of America;

(B) at the date of the latest available balance sheet read by such accountants, or at a subsequent specified date not more than three business days prior to the date of this Agreement, there was any change in the common stock or any increase in long-term debt of the Company or any decrease in consolidated net current assets or shareholders’ equity, as compared with amounts shown on the latest balance sheet incorporated by reference in the Preliminary and Final Offering Circular; or

(C) for the period from the closing date of the latest income statement incorporated by reference in the Preliminary and Final Offering Circular to the closing date of the latest available income statement read by such accountants there were any decreases, as compared with the corresponding period of the previous year, in consolidated operating revenues, operating income, or net income;

except in all cases set forth in clauses (B) and (C) above for changes, increases or decreases which the Preliminary and Final Offering Circular disclose have occurred or may occur or which are described in such letter; and

(iv) they have compared specified dollar amounts (or percentages derived from such dollar amounts) and other financial information contained in the Preliminary Offering Circular, each other document comprising any part of the General Disclosure Package, the Final Offering Circular and each item of Supplemental Marketing Material (other than any Supplemental Marketing Material that is an electronic road show) and the Exchange Act Reports (to the extent that such dollar amounts, percentages and other financial information are derived from the general accounting records of the Company and its subsidiaries subject to the internal controls of the Company’s accounting system or are derived directly from such records by analysis or computation) with the results obtained from inquiries, a reading of such general accounting records and other procedures specified in such letter and have found such dollar amounts, percentages and other financial information to be in agreement with such results, except as otherwise specified in such letter.

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(b)Subsequent to the execution and delivery of this Agreement, there shall not have occurred (i) any change, or any development or event involving a prospective change, in the condition (financial or other), business, properties or results of operations of the Company and its subsidiaries taken as one enterprise which, in the reasonable judgment of a majority in interest of the Purchasers including the Representatives, is material and adverse and makes it impractical or inadvisable to proceed with completion of the offering or the sale of and payment for the Offered Securities; (ii) any downgrading in the rating of any debt securities of the Company by any “nationally recognized statistical rating organization” (as defined for purposes of Rule 436(g) under the Securities Act), or any public announcement that any such organization has under surveillance or review its rating of any debt securities of the Company (other than an announcement with positive implications of a possible upgrading, and no implication of a possible downgrading, of such rating)or any announcement that the Company has been placed on negative outlook; (iii) any change in U.S. or international financial, political or economic conditions or currency exchange rates or exchange controls as would, in the reasonable judgment of a majority in interest of the Purchasers including the Representatives, be likely to prejudice materially the success of the proposed issue, sale or distribution of the Offered Securities, whether in the primary market or in respect of dealings in the secondary market, (iv) any material suspension or material limitation of trading in securities generally on the New York Stock Exchange, or any setting of minimum prices for trading on such exchange, (v) any suspension of trading of any securities of the Company on any exchange or in the over-the-counter market; (vi) any banking moratorium declared by U.S. Federal or New York authorities; (vii) any major disruption of settlements of securities or clearance services in the United States or (viii) any attack on, outbreak or escalation of hostilities or act of terrorism involving the United States, any declaration of war by Congress or any other national or international calamity or emergency if, in the reasonable judgment of a majority in interest of the Purchasers including the Representatives, the effect of any such attack, outbreak, escalation, act, declaration, calamity or emergency makes it impractical or inadvisable to proceed with completion of the offering or sale of and payment for the Offered Securities.

(c) The Purchasers shall have received an opinion, dated the Closing Date, from:

(i)Leonard, Street & Deinard, Professional Association, counsel for the Company, substantially in the form attached hereto as Schedule D.

(ii)Thomas Knapp, Esq., Vice President, General Counsel and Corporate Secretary of the Company, substantially in the form attached hereto as Schedule E.

(iii)Wayne Harper, Esq., counsel in the legal department of the NorthWestern Energy division of the Company, substantially in the form attached hereto as Schedule F.

(v)Browning, Kaleczyc, Berry & Hoven, P.C., Montana counsel to the Company, substantially in the form attached hereto as Schedule G.

(d)The Purchasers shall have received from Dewey Ballantine LLP, counsel for the Purchasers, such opinion, dated the Closing Date, with respect to the incorporation of the Company, the validity of the Offered Securities, the Final Offering Circular and the General Disclosure Package, the exemption from registration for the offer and sale of the Offered Securities by the Company to the several Purchasers and the resales by the several Purchasers as contemplated hereby and other related matters as the Representatives may reasonably require, and the Company shall have furnished to such counsel such documents as they reasonably request for the purpose of enabling them to pass upon such matters.

(e)The Purchasers shall have received a certificate, dated the Closing Date, of the President, any Vice President or Treasurer and a principal financial or accounting officer of the Company in which such officers, to the best of their knowledge after reasonable investigation, shall certify, on behalf of the Company, that the representations and warranties of the Company in this Agreement are true and correct, that the Company has complied with all agreements and satisfied all conditions on its part to be performed or satisfied hereunder at or prior to the Closing Date, and that, subsequent to the date of the most recent financial statements incorporated by reference in the Preliminary and Final Offering Circular there has been no material adverse change, nor any development or event involving a prospective material adverse change, in the

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condition (financial or other), business, properties or results of operations of the Company and its subsidiaries taken as a whole except as set forth in the General Disclosure Package and the Final Offering Circular or as described in such certificate.

(f)The Purchasers shall have received a letter, dated the Closing Date, of Deloitte & Touche, LLP which meets the requirements of subsection (a) of this Section, except that the specified date referred to in such subsection will be a date not more than three days prior to the Closing Date for the purposes of this subsection.

The Company will furnish the Purchasers with such conformed copies of such opinions, certificates, letters and documents as the Purchasers reasonably request. The Representatives may in their sole discretion waive on behalf of the Purchasers compliance with any conditions to the obligations of the Purchasers hereunder.

8. Indemnification and Contribution. (a) The Company will indemnify and hold harmless each Purchaser, its partners, members, directors, officers and its affiliates and each person, if any, who controls such Purchaser within the meaning of Section 15 of the Securities Act, against any losses, claims, damages or liabilities, joint or several, to which such Purchaser may become subject, under the Securities Act or the Exchange Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions in respect thereof) arise out of or are based upon any untrue statement or alleged untrue statement of any material fact contained in the Preliminary Offering Circular or the Final Offering Circular, in each case as amended or supplemented, or any Issuer Free Writing Communication or Supplemental Marketing Material or the Exchange Act Reports, or arise out of or are based upon the omission or alleged omission to state therein a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading, including any losses, claims, damages or liabilities arising out of or based upon the Company’s failure to perform its obligations under Section 5(a) of this Agreement, and will reimburse each Purchaser for any legal or other expenses reasonably incurred by such Purchaser in connection with investigating or defending any such loss, claim, damage, liability or action as such expenses are incurred; provided, however, that the Company will not be liable in any such case to the extent that any such loss, claim, damage or liability arises out of or is based upon an untrue statement or alleged untrue statement in or omission or alleged omission from any of such documents in reliance upon and in conformity with written information furnished to the Company by any Purchaser through the Representatives specifically for use therein, it being understood and agreed that the only such information consists of the information described as such in subsection (b) below.

(b) Each Purchaser will severally and not jointly indemnify and hold harmless the Company, its affiliates, its directors and officers and each person, if any, who controls the Company within the meaning of Section 15 of the Securities Act, against any losses, claims, damages or liabilities to which the Company may become subject, under the Securities Act or the Exchange Act or otherwise, insofar as such losses, claims, damages or liabilities (or actions in respect thereof) arise out of or are based upon any untrue statement or alleged untrue statement of any material fact contained in the Preliminary Offering Circular or the Final Offering Circular, in each case as amended or supplemented, or any Issuer Free Writing Communication or Supplemental Marketing Material, or arise out of or are based upon the omission or the alleged omission to state therein a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading, in each case to the extent, but only to the extent, that such untrue statement or alleged untrue statement or omission or alleged omission was made in reliance upon and in conformity with written information furnished to the Company by such Purchaser through the Representatives specifically for use therein, and will reimburse any legal or other expenses reasonably incurred by the Company in connection with investigating or defending any such loss, claim, damage, liability or action as such expenses are incurred, it being understood and agreed that the only such information furnished by any Purchaser consists of (i) the following information in the Preliminary and Final Offering Circular furnished on behalf of each Purchaser: the fourth sentence of the second paragraph of text under the caption “Risk Factors - Risks relating to the Bonds and the Offering - If an active trading market does not develop for the bonds, you may not be able to resell them at or above the price you paid for them, or at all,” the third paragraph, the sixth paragraph, the second and third sentences of the eighth paragraph, and the tenth paragraph under the caption “Plan of Distribution” provided, however, that the Purchasers shall not be liable for any losses, claims, damages or liabilities arising out of or based upon the Company’s failure to perform its obligations under Section 5(a) of this Agreement.

(c) Promptly after receipt by an indemnified party under this Section of notice of the commencement of any action, such indemnified party will, if a claim in respect thereof is to be made against the indemnifying party

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under subsection (a) or (b) above, notify the indemnifying party of the commencement thereof; but the failure to notify the indemnifying party shall not relieve it from any liability that it may have to an indemnified party otherwise than under subsection (a) or (b) above to the extent it is not materially prejudiced as a result thereof. In case any such action is brought against any indemnified party and it notifies the indemnifying party of the commencement thereof, the indemnifying party will be entitled to participate therein and, to the extent that it may wish, jointly with any other indemnifying party similarly notified, to assume the defense thereof, with counsel reasonably satisfactory to such indemnified party (who shall not, except with the consent of the indemnified party, be counsel to the indemnifying party), and after notice from the indemnifying party to such indemnified party of its election so to assume the defense thereof, the indemnifying party will not be liable to such indemnified party under this Section for any legal or other expenses subsequently incurred by such indemnified party in connection with the defense thereof other than reasonable costs of investigation. No indemnifying party shall, without the prior written consent of the indemnified party, effect any settlement of any pending or threatened action in respect of which any indemnified party is or could have been a party and indemnity could have been sought hereunder by such indemnified party unless such settlement (i) includes an unconditional release of such indemnified party from all liability on any claims that are the subject matter of such action and (ii) does not include a statement as to or an admission of fault, culpability or failure to act by or on behalf of any indemnified party.

(d) If the indemnification provided for in this Section is unavailable or insufficient to hold harmless an indemnified party under subsection (a) or (b) above, then each indemnifying party shall contribute to the amount paid or payable by such indemnified party as a result of the losses, claims, damages or liabilities referred to in subsection (a) or (b) above (i) in such proportion as is appropriate to reflect the relative benefits received by the Company on the one hand and the Purchasers on the other from the offering of the Offered Securities or (ii) if the allocation provided by clause (i) above is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) above but also the relative fault of the Company on the one hand and the Purchasers on the other in connection with the statements or omissions which resulted in such losses, claims, damages or liabilities as well as any other relevant equitable considerations. The relative benefits received by the Company on the one hand and the Purchasers on the other shall be deemed to be in the same proportion as the total net proceeds from the offering (before deducting expenses) received by the Company bear to the total discounts and commissions received by the Purchasers from the Company under this Agreement. The relative fault shall be determined by reference to, among other things, whether the untrue or alleged untrue statement of a material fact or the omission or alleged omission to state a material fact relates to information supplied by the Company or the Purchasers and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such untrue statement or omission. The amount paid by an indemnified party as a result of the losses, claims, damages or liabilities referred to in the first sentence of this subsection (d) shall be deemed to include any legal or other expenses reasonably incurred by such indemnified party in connection with investigating or defending any action or claim which is the subject of this subsection (d). Notwithstanding the provisions of this subsection (d), no Purchaser shall be required to contribute any amount in excess of the amount by which the total price at which the Offered Securities purchased by it were resold exceeds the amount of any damages which such Purchaser has otherwise been required to pay by reason of such untrue or alleged untrue statement or omission or alleged omission. The Purchasers’ obligations in this subsection (d) to contribute are several in proportion to their respective purchase obligations and not joint.

(e) The obligations of the Company under this Section shall be in addition to any liability which the Company may otherwise have and shall extend, upon the same terms and conditions, to each person, if any, who controls any Purchaser within the meaning of the Securities Act or the Exchange Act; and the obligations of the Purchasers under this Section shall be in addition to any liability which the respective Purchasers may otherwise have and shall extend, upon the same terms and conditions, to each person, if any, who controls the Company within the meaning of the Securities Act or the Exchange Act.

9. Default of Purchasers. If any Purchaser or Purchasers default in their obligations to purchase Offered Securities hereunder and the aggregate principal amount of Offered Securities that such defaulting Purchaser or Purchasers agreed but failed to purchase does not exceed 10% of the total principal amount of Offered Securities, the Representatives may make arrangements satisfactory to the Company for the purchase of such Offered Securities by other persons, including any of the Purchasers, but if no such arrangements are made by the Closing Date, the non-defaulting Purchasers shall be obligated severally, in proportion to their respective commitments hereunder, to purchase the Offered Securities that such defaulting Purchasers agreed but failed to purchase. If any Purchaser or Purchasers so default and the aggregate principal amount of Offered Securities with respect to which such default or defaults occur

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exceeds 10% of the total principal amount of Offered Securities and arrangements satisfactory to the Representatives and the Company for the purchase of such Offered Securities by other persons are not made within 36 hours after such default, this Agreement will terminate without liability on the part of any non-defaulting Purchaser or the Company, except as provided in Section 10. As used in this Agreement, the term “Purchaser” includes any person substituted for a Purchaser under this Section. Nothing herein will relieve a defaulting Purchaser from liability for its default.

10. Survival of Certain Representations and Obligations. The respective indemnities, agreements, representations, warranties and other statements of the Company or its officers and of the several Purchasers set forth in or made pursuant to this Agreement will remain in full force and effect, regardless of any investigation, or statement as to the results thereof, made by or on behalf of any Purchaser, the Company or any of their respective representatives, officers or directors or any controlling person, and will survive delivery of and payment for the Offered Securities. If this Agreement is terminated pursuant to Section 9 or if for any reason the purchase of the Offered Securities by the Purchasers is not consummated, the Company shall remain responsible for the expenses to be paid or reimbursed by it pursuant to Section 5 and the respective obligations of the Company and the Purchasers pursuant to Section 8 shall remain in effect. If the purchase of the Offered Securities by the Purchasers is not consummated for any reason other than solely because of the termination of this Agreement pursuant to Section 9 or the occurrence of any event specified in clause (iii), (iv), (vi), (vii) or (viii) of Section 7(b), the Company will reimburse the Purchasers for all out-of-pocket expenses (including fees and disbursements of counsel) reasonably incurred by them in connection with the offering of the Offered Securities.

11. Notices. All communications hereunder will be in writing and, if sent to the Purchasers will be mailed, delivered or telegraphed and confirmed to the Purchasers, c/o Credit Suisse Securities (USA) LLC, Eleven Madison Avenue, New York, N.Y. 10010-3629, Attention: LCD-IBD, or, if sent to the Company, will be mailed, delivered or telegraphed and confirmed to it at 125 S. Dakota Avenue, Sioux Falls, S.D. 57104-6403, Attention: Paul Evans, with a copy to Leonard, Street and Deinard, 150 South Fifth Street, Suite 2300, Minneapolis, MN 55402, Attention: Tammie S. Ptacek (fax 612-335-7246); provided, however, that any notice to a Purchaser pursuant to Section 8 will be mailed, delivered or telegraphed and confirmed to such Purchaser.

12. Successors. This Agreement will inure to the benefit of and be binding upon the parties hereto and their respective successors and the controlling persons referred to in Section 8, and no other person will have any right or obligation hereunder, except that holders of Offered Securities shall be entitled to enforce the agreements for their benefit contained in the second and third sentences of Section 5(b) hereof against the Company as if such holders were parties thereto.

13. Representation of Purchasers. You will act for the several Purchasers in connection with this purchase, and any action under this Agreement taken by you jointly will be binding upon all the Purchasers.

14. Counterparts. This Agreement may be executed in any number of counterparts, each of which shall be deemed to be an original, but all such counterparts shall together constitute one and the same Agreement.

15. Absence of Fiduciary Relationship. The Company acknowledges and agrees that:

(a) the Representatives have been retained solely to act as initial purchasers in connection with the initial purchase, offering and resale of the Offered Securities and that no fiduciary, advisory or agency relationship between the Company and the Representatives has been created in respect of any of the transactions contemplated by this Agreement or the Preliminary or Final Offering Circular, irrespective of whether the Representatives have advised or are advising the Company on other matters;

(b) the purchase price of the Offered Securities set forth in this Agreement was established by the Company following discussions and arms-length negotiations with the Representatives and the Company is capable of evaluating and understanding and understands and accepts the terms, risks and conditions of the transactions contemplated by this Agreement;

(c) the Company has been advised that the Representatives and their affiliates are engaged in a broad range of transactions which may involve interests that differ from those of the Company and that the Representatives

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have no obligation to disclose such interests and transactions to the Company by virtue of any fiduciary, advisory or agency relationship; and

(d) the Company waives, to the fullest extent permitted by law, any claims it may have against the Representatives for breach of fiduciary duty or alleged breach of fiduciary duty and agrees that the Representatives shall have no liability (whether direct or indirect) to the Company in respect of such a fiduciary claim or to any person asserting a fiduciary claim on behalf of or in right of the Company, including stockholders, employees or creditors of the Company.

16. Applicable Law. This Agreement shall be governed by, and construed in accordance with, the laws of the State of New York without regard to principles of conflicts of laws.

The Company hereby submits to the non-exclusive jurisdiction of the Federal and state courts in the Borough of Manhattan in The City of New York in any suit or proceeding arising out of or relating to this Agreement or the transactions contemplated hereby.

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                If the foregoing is in accordance with the Purchasers’ understanding of our agreement, kindly sign and return to us one of the counterparts hereof, whereupon it will become a binding agreement between the Company and the several Purchasers in accordance with its terms.

Very truly yours,

NORTHWESTERN CORPORATION

By		/s/ Paul J. Evans
	Title: Treasurer

The foregoing Purchase Agreement

	is hereby confirmed and accepted
as of the date first above written.

CREDIT SUISSE SECURITIES (USA) LLC

DEUTSCHE BANK SECURITIES INC.

Acting on behalf of themselves

and as the Representatives of

the several Purchasers

By: CREDIT SUISSE SECURITIES (USA) LLC

By /s/ Jamie Welch

Title: Managing Director

By: DEUTSCHE BANK SECURITIES INC.

By /s/ Ben Smilchensky

Title: Managing Director

By /s/ Ryan Montgomery

Title: Director

SCHEDULE A

I. Purchase Price

The purchase price to be paid by the Purchasers for the Offered Securities shall be as follows:

Price to Public	Purchasers’ Discount	Purchasers’ Purchase Price
99.951%	0.70%	99.251%

II. Principal Amount to be Purchased

Manager	PrincipalAmount of Offered Securities
Credit Suisse Securities (USA) LLC	$52,500,000
Deutsche Bank Securities Inc.	52,500,000
Wachovia Capital Markets, LLC	15,000,000
KeyBanc Capital Markets, a Division of McDonald Investments Inc.	6,000,000
LaSalle Financial Services, Inc.	6,000,000
Piper Jaffray & Co.	6,000,000
Scotia Capital (USA) Inc.	6,000,000
Wedbush Morgan Securities Inc.	6,000,000
Total	$150,000,000

SCHEDULE B

NorthWestern Investments, LLC

Blue Dot Capital, LLC

Blue Dot Services, LLC

Clark Fork and Blackfoot, L.L.C.

NorthWestern Services Corporation

Nekota Resources, Inc.

NorthWestern Energy Development, LLC

NorthWestern Generation I, LLC

Montana Megawatts I, LLC

NorthWestern Energy Marketing, LLC

Canadian-Montana Pipe Line Corporation

Risk Partners Assurance, Ltd.

SCHEDULE C

NorthWestern Corporation

$150,000,000 6.04% First Mortgage Bonds due 2016

Issuer:	NorthWestern Corporation
Security:	First Mortgage Bonds
Type:	144A (with Registration Rights)
Ratings:	Baa3 (Stable)/BBB- (CreditWatch Negative)/BBB (Stable)
Trade Date:	September 6, 2006
Settlement Date:	September 13, 2006
Maturity Date:	September 1, 2016
Benchmark Treasury:	4.875% UST due August 15, 2016
Benchmark Treasury Yield:	4.797%
Benchmark Treasury Price:	100-19+
Reoffer Spread to Benchmark:	+125 bps
Reoffer Yield:	6.047%
Coupon:	6.04%
Price:	99.951%
Redemption Provisions:	Make whole call T+ 20 bps
Coupon Payment Dates:	Semi-annually on March 1 and September 1, beginning March 1, 2007
CUSIP:	668074 AN 7 (144A) U66630 AD 3 (Reg S)
Day count:	30/360
Joint-Bookrunning Managers:	Credit Suisse Securities (USA) LLC Deutsche Bank Securities Inc.
Senior Co-Managers:	Wachovia Capital Markets, LLC
Co-Managers:	KeyBanc Capital Markets, a Division of McDonald Investments Inc. Piper Jaffray & Co. Wedbush Morgan Securities Inc. LaSalle Financial Services, Inc. Scotia Capital (USA) Inc.

SCHEDULE D

Opinion of Leonard, Street and Deinard

(Covering New York, Delaware General Corporation and Federal laws)

1.   The Company is a validly existing corporation in good standing under the laws of the State of Delaware, and has the corporate power and authority to own its properties and to transact the business in which it is engaged.

2.   The Company has the corporate power and authority to execute and deliver (or to assume), and to perform its obligations under, each of the Registration Rights Agreement, the Purchase Agreement, the Offered Securities and the Mortgage (collectively, the “Transaction Documents”) and has taken or caused to be taken all necessary corporate action to authorize the execution and delivery (or the assumption) and performance by it of each of the Transaction Documents.

3.    Each of the Transaction Documents has been duly executed and delivered by the Company (other than the Mortgage (excluding the Supplemental Indenture) and the first twenty-five indentures supplemental thereto, each of which has been duly assumed by the Company).

4.    Each of the Transaction Documents constitutes the legal, valid and binding obligation of the Company, enforceable against the Company in accordance with its terms.

5.    The Offered Securities have been duly and validly issued under the Mortgage, will be “Outstanding” under and as defined in the Mortgage and will be entitled to the benefit and security of the Mortgage equally and ratably with all other bonds outstanding under the Mortgage.

6.    The execution and delivery (or the assumption) of the Transaction Documents by the Company, and the performance by it of its obligations thereunder, do not (i) violate (a) the Delaware General Corporation Law, or (b) Federal or New York State law or regulation, or (ii) violate any order or decree of any Federal or New York State court or governmental instrumentality applicable to the Company and of which such counsel has knowledge, or (iii) conflict with, or result in a breach of, constitute a default under, or result in the creation or imposition of any Lien upon any of the property of the Company pursuant to any material agreement of the Company identified on Schedule A to such opinion, except as would not cause or result in a Material Adverse Effect or (v) violate any provision of the certificate of incorporation or bylaws of the Company.

7.   No consent, approval, authorization or order of, or filing with, any federal governmental agency or body or any court is required to authorize, or is otherwise required in connection with, the execution and delivery (or, if applicable, assumption) and performance of the Transaction Documents by the Company, including, without limitation, the issuance by the Company of the Offered Securities, upon the terms and subject to the conditions provided in the Transaction Documents (collectively, the “Issuance of Bonds”), except (a) such as may be required under or by (i) the Securities Act and (ii) the Trust Indenture Act, with respect to the Registration Rights Agreement and the transactions contemplated thereunder, (b) the approval of the Issuance of Bonds by the Federal Energy Regulatory Commission (“FERC”), which approval is contained in FERC’s letter order dated August 18, 2006 and which letter order is in full force and effect; and the Issuance of Bonds is in conformity with the terms of such letter order (including, without limitation, the aggregate amounts of securities authorized to be issued thereby).

8.    The Company is not, and after giving effect to the application of the proceeds of the Offered Securities, will not be (solely as a result of such application), an “investment company” or a company “controlled” by an “investment company” within the meaning of the Investment Company Act of 1940, as amended.

9.    It is not necessary, in connection with the issuance and sale of the Offered Securities in accordance with the Purchase Agreement and in connection with the issuance and delivery to the Trustee of the Offered Securities under the circumstances contemplated by the Indenture to register the Offered Securities under the Securities Act of 1933, as amended, or to qualify any indenture in respect thereof under the Trust Indenture Act of 1939, as amended.

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10.   No filings with any governmental authority or body are required in the state of Delaware in order to perfect the lien of the Mortgage upon any property of the Company (other than property owned by the Company in the states of Montana and Wyoming) described in the Mortgage as subject to the lien thereof.

11.  Each of the Transaction Documents conforms to the description thereof contained in the General Disclosure Package and the Final Offering Circular.

12.  The execution, delivery and performance of the Mortgage, the Registration Rights Agreement and the Purchase Agreement and the issuance and sale of the Offered Securities and compliance with the terms thereof will not result in a breach or violation of any of the terms and provisions of, or constitute a default or result in the creation or imposition of any Lien (other than the Liens of the Mortgage) upon any property or assets of the Company under, (i) any statute, any rule, regulation or order of any governmental agency or body or any court having jurisdiction over the Company or any subsidiary of the Company or any of their properties that in such counsel’s experience customarily applies to transactions of the type contemplated by this Agreement, the Mortgage, the Registration Rights Agreement and the Offered Securities, (ii) any agreement or instrument known to such counsel to which the Company or any such subsidiary is a party or by which the Company or any such subsidiary is bound or to which any of the properties of the Company or any such subsidiary is subject, or (iii) the certificate of incorporation or by-laws of the Company or any such subsidiary, except, in the cases of clauses (i) and (ii) above, for any such breach, violation, or default that would not result in a Material Adverse Effect.

13.  The FERC has issued appropriate authorization with respect to the issuance of the Offered Securities in accordance with the Mortgage; to such counsel’s knowledge, after due inquiry, such authorizations are in full force and effect and the issuance of the Offered Securities is in conformity with the terms of such authorizations and no other consent, approval, authorization or order of, or filing with, any governmental agency or body or any court is required for the consummation by the Company of the transactions contemplated by the Purchase Agreement and the Registration Rights Agreement in connection with the issuance or sale of the Offered Securities, except such as may be required under state securities laws and except for the order of the Commission declaring the Exchange Offer Registration Statement or the Shelf Registration Statement effective.

Based upon such counsel’s participation in conferences and review of documents pursuant to such counsel’s engagement by the Company, such counsel has no reason to believe that the Final Offering Circular, or any amendment or supplement thereto, or any Exchange Act Report, as of the date hereof and as of the Closing Date, contained any untrue statement of a material fact or omitted to state any material fact required to be stated therein or necessary to make the statements therein not misleading; such counsel has no reason to believe that the General Disclosure Package, as of the Applicable Time and as of the Closing Date, contained any untrue statement of a material fact or omitted to state any material fact required to be stated therein or necessary to make the statements therein not misleading; the descriptions in the Final Offering Circular and the Exchange Act Reports of statutes, legal and governmental proceedings and contracts and other documents are accurate and fairly present the information required to be shown; it being understood that such counsel expresses no opinion as to (i) the financial statements or other financial data contained in the General Disclosure Package, the Final Offering Circular and the Exchange Act Reports, or (ii) the information in the Preliminary and Final Offering Circular identified in Section 8(b) of the Purchase Agreement as having been furnished on behalf of each Purchaser.

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SCHEDULE E

Opinion of Thomas Knapp, Esq.

1.    The Company has been duly incorporated and is an existing corporation in good standing under the laws of the State of Delaware, has all requisite corporate power and authority (a) to execute, deliver (or assume) and perform its obligations under the Registration Rights Agreement, the Purchase Agreement, the Mortgage and the Offered Securities (collectively, the “Transaction Documents”), and (b) to own and encumber its assets and conduct its business as described in the General Disclosure Package, the Final Offering Circular and the Exchange Act Reports. The Company is duly qualified to transact business, and is in good standing as a foreign corporation, in the States of Montana, Wyoming, South Dakota, Nebraska, North Dakota and Iowa.

2.    There are no “significant subsidiaries” (as the term “significant subsidiary” is defined in Rule 1-02 of Regulation S-X promulgated by the Securities and Exchange Commission) of the Company as of the date of such opinion.

3.    The authorized, issued and outstanding capital stock of the Company is as set forth in the Final Offering Circular in the column entitled “Actual” under the caption “Capitalization” (except for subsequent issuances, if any, pursuant to reservations, agreements or employee benefit plans referred to in the Final Offering Circular).

4.    Each of the Transaction Documents has been duly authorized by all necessary corporate action on the part of, and duly executed and delivered (or assumed), by, the Company. The Offered Securities have been duly and validly authorized and issued.

5.   The Registration Rights Agreement and this Agreement constitute the valid and legally binding obligations of the Company, enforceable against the Company in accordance with their terms, subject to: (i) the effect of any applicable bankruptcy, insolvency, reorganization, moratorium or similar law affecting creditors’ rights generally, including without limitation fraudulent transfer or conveyance laws; (ii) the effect of public policy considerations or court decisions which may limit rights to obtain indemnification or contribution; and (iii) the effect of general principles of equity (including, without limitation, concepts of materiality, reasonableness, good faith and fair dealings and the availability of equitable remedies, including, without limitation, specific performance and equitable relief), regardless of whether enforceability is considered in a proceeding in equity or at law.

6.    The execution and delivery (or the assumption) by the Company of the Transaction Documents, and the performance by the Company of its obligations thereunder, do not: (i)  violate any of the terms, conditions or provisions of the Certificate of Incorporation or bylaws of the Company, as in effect as of the Closing Date; (ii)  violate any of the terms, conditions or provisions of any order, writ, judgment, decree or award of any court or administrative decree binding on or affecting the Company; (iii) result in a breach of, constitute a default under, require the termination of, or the approval or consent of any Person under, any material agreement to which the Company is a party or by which the Company or any of its properties is bound, which breach, default or termination, or the failure to obtain such approval or consent, could reasonably be expected to have a Material Adverse Effect; or (iv) to such counsel’s knowledge, result in or require the creation or imposition of any Lien whatsoever upon or with respect to any of the properties or assets of the Company (other than the Lien of the Mortgage).

7.    To such counsel’s knowledge, other than as disclosed in the General Disclosure Package and the Final Offering Circular, (i) there are no material judgments outstanding against the Company, and (ii) there is no action, suit, proceeding, governmental investigation or arbitration, at law or in equity or before any Governmental Authority, pending or overtly threatened against the Company or any of its properties, which could reasonably be expected to have a Material Adverse Effect, or which purports to affect the legality, validity or enforceability of the Transaction Documents or which prevents, enjoins or prohibits, or seeks to prevent, enjoin or prohibit, the execution or enforcement of the Transaction Documents or the consummation of the transactions contemplated by the Transaction Documents.

8.    The Company is not subject to regulation as a utility company under any statute or regulation of the State of South Dakota or the State of Nebraska such that its ability to incur indebtedness or to consummate the transactions contemplated by the Transaction Documents is limited. The Company is not subject to regulation as a utility company in any states other than Montana, South Dakota and Nebraska (and the Company is not subject to such regulation in the States of Iowa, North Dakota and Delaware).

9.    No filings with any governmental authority or body are required in the state of South Dakota in order to perfect the lien of the Mortgage upon any property of the Company (other than property owned by the Company in the states of Montana and Wyoming) described in the Mortgage as subject to the lien thereof.

10.  The Federal Energy Regulatory Commission (FERC) has issued appropriate authorization with respect to the issuance and sale of the Offered Securities in accordance with this Agreement; the Montana Public Service Commission (MPSC) has issued appropriate authorization with respect to the issuance and delivery of the Offered Securities in accordance with the Mortgage and this Agreement; to such counsel’s knowledge, after due inquiry, such authorizations are in full force and effect and the issuance of the Offered Securities is in conformity with the terms of such authorizations and no other consent, approval, authorization or order of, or filing with, any governmental agency or body or any court is required for the execution, delivery or consummation of the transactions contemplated by the Transaction Documents, except (i) in the case of any thereof related to the operation by the Company of its properties or the filing or recording of documents or instruments in respect of the Liens created or purported to be created thereunder, which will be made in the ordinary course of the Company’s business, (ii) those which the failure to obtain would not have a Material Adverse Effect, or (iii) such as may be required under state securities laws and except for the order of the Commission declaring the Exchange Offer Registration Statement or the Shelf Registration Statement effective and except for the filing of a notice of sale on Form D as required by Rule 503 of Regulation D of the Securities Act. With respect to the opinions related to approval by the FERC, such counsel shall be entitled to rely on the opinion of even date herewith of Leonard, Street and Deinard Professional Association, and with respect to the opinions related to approval by the MPSC, such counsel shall be entitled to rely on the opinion of even date herewith of Browning, Kaleczyc, Berry & Hoven, P.C.

11.  Neither the Company nor any of its subsidiaries is in violation of its respective charter or by-laws or in default in the performance of any obligation, agreement, covenant or condition contained in any indenture, loan agreement, mortgage, lease or other agreement or instrument that is material to the Company and its subsidiaries, taken as a whole, to which the Company or any of its subsidiaries is a party or by which the Company or any of its subsidiaries or their respective property is bound.

12.  To such counsel’s knowledge, there are no contracts or agreements between the Company and any person granting such person the right to require the Company to file a registration statement under the Securities Act with respect to any securities of the Company or to require the Company to include such securities with the Exchange Securities registered pursuant to any Exchange Offer Registration Statement as required pursuant to the Registration Rights Agreement.

13.  To such counsel’s knowledge, there are no material franchises, contracts, indentures, mortgages, loan agreements, notes, leases or other instruments required to be described or filed as an exhibit to the Company’s Exchange Act Reports other than those described or referred to therein or filed or incorporated by reference as exhibits thereto.

Such counsel has no reason to believe that the Final Offering Circular, or any amendment or supplement thereto, or any Exchange Act Report, as of the date hereof and as of the Closing Date, contained any untrue statement of a material fact or omitted to state any material fact required to be stated therein or necessary to make the statements therein not misleading; such counsel has no reason to believe that the General Disclosure Package, as of the Applicable Time and as of the Closing Date, contained any untrue statement of a material fact or omitted to state any material fact required to be stated therein or necessary to make the statements therein not misleading; the descriptions in the Final Offering Circular and the Exchange Act Reports of statutes, legal and governmental proceedings and contracts and other documents are accurate and fairly describe such statutes, legal and governmental proceedings and contracts; it being understood that such counsel need express no opinion as to (i) the financial statements or other financial data contained in the General Disclosure Package, the Final Offering Circular and the Exchange Act Reports or (ii) the

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information in the Preliminary and Final Offering Circular identified in Section 8(b) of the Purchase Agreement as having been furnished on behalf of each Purchaser.

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SCHEDULE F

Opinion of

Wayne Harper, Esq.

i.              The Company has valid and subsisting franchise rights, licenses, permits, and other authorizations, free from any restrictions or conditions which are unusual or unduly burdensome, sufficient for the ownership of its properties and the conduct of its utility business in the States of Montana and Wyoming;

ii.            The Mortgage has been duly authorized, executed and delivered (and/or duly assumed) by the Company (or its predecessors) and (assuming due authorization, execution and delivery by the Trustees (or their predecessors)), is a valid and binding obligation of the Company enforceable against the Company in accordance with its terms, except as the same may be limited by (a) the laws of the jurisdictions in which the physical properties covered thereby are located affecting the remedies for the enforcement of the security provided therein (which laws do not, in the opinion of such counsel, make inadequate the remedies necessary for the realization of the benefits of such security) and (b) applicable bankruptcy, reorganization or similar laws affecting creditors’ rights generally;

iii.           The Mortgage, excluding the Supplemental Indenture (but including any necessary related financing statements), has been filed and recorded wherever and to the extent necessary to perfect the lien thereof upon the properties now owned by the Company in the States of Montana and Wyoming and intended to be subject thereto; all fees or taxes in connection therewith have been paid and no other filing or recordation is presently necessary in order to perfect the lien of the Mortgage on such properties; (b) the Mortgage, excluding the Supplemental Indenture, now constitutes, and the Mortgage, when the Supplemental Indenture shall have been duly filed for recording and is recorded, will continue to constitute, a legally valid and directly enforceable first mortgage lien (subject only to the matters described in (v) below and the exception set forth in (ii) above) for the equal and proportionate security of the Mortgage Bonds and of the first mortgage bonds of other series heretofore issued and hereafter to be issued under the Mortgage, upon the mortgaged properties specifically described therein as subject to the lien thereof (excluding all properties heretofore disposed of in accordance with the terms thereof or expressly excepted therefrom) and such mortgaged properties, other than said excluded and excepted properties, comprise and constitute substantially all of the utility property of the Company in the States of Montana and Wyoming; and (c) the after-acquired property clause in the Mortgage subjects to the lien of the Mortgage all after-acquired utility property of the Company in the States of Montana and Wyoming (except such thereof as is expressly excepted from the lien of the Mortgage);

iv.            The Supplemental Indenture has not yet been filed or recorded, but no such filing and recording is necessary to perfect the lien of the Mortgage upon the properties now owned by the Company in the States of Montana and Wyoming and intended to be subject thereto or to extend such lien for the benefit of the Offered Securities; (b) no re-recording or refiling of the Mortgage or any other instruments or documents (except for periodic filings which extend the effectiveness of financing statements) is required to preserve and protect the lien of the Mortgage; and (c) under the present law of the States of Montana and Wyoming, no further supplemental indentures or other instruments or documents are required to be executed, filed and/or recorded to extend the lien of the Mortgage to after-acquired property; however, the Company is required by the terms of the Mortgage to promptly record and file the Supplemental Indenture;

v.             The Company has good and marketable fee simple title to all of the real properties, and good and marketable title to all other properties, located in the States of Montana and Wyoming owned by it, subject only to the lien of the Mortgage and such other Excepted Encumbrances and Permitted Encumbrances (each as defined in the Mortgage), and such other liens, encumbrances, defects and irregularities which are customarily found with respect to properties of like size and character and which, in the opinion of such counsel, do not materially impair the use of the property affected thereby in the operation of the utility business of the Company in the States of Montana and Wyoming; and the properties in the States of Montana and Wyoming held under leases by the Company are held under valid and enforceable leases subject only to such exceptions as do not materially interfere with the conduct of the utility business of the Company in the States of Montana and Wyoming.

SCHEDULE G

Opinion of

BROWNING, KALECZYC, BERRY & HOVEN, P.C.,

Montana counsel to the Company

1.             The execution and delivery of the this Agreement, the Offered Securities and the Mortgage (the “Transaction Documents”) by the Company, and the performance by it of its obligations thereunder do not violate any Montana law or regulation, or violate any order or decree of any Montana State court or governmental instrumentality applicable to the Company and of which such counsel has knowledge.

2.             No consent, approval or authorization of, or filing with, any Montana State governmental or public body or authority is required to authorize, or is otherwise required in connection with, the execution, delivery and performance of the Transaction Documents by the Company, including, without limitation, the incurrence of indebtedness or the issuance of first mortgage bonds covering Montana property as contemplated by the Transaction Documents, except for the approval of the Montana Public Service Commission (“MPSC”), which approval has been duly and validly obtained and is subject to the terms and conditions stated in such order.

3.             The issuance of the Offered Securities pursuant to and in accordance with the Transaction Documents, including the Supplemental Indenture, conforms with the MPSC Order.

EX-10

$150,000,000

NorthWestern Corporation

6.04% First Mortgage Bonds due 2016

REGISTRATION RIGHTS AGREEMENT

September 13, 2006

Credit Suisse Securities (USA) LLC

Deutsche Bank Securities Inc.,

As Representatives of the Several Initial Purchasers

c/o Credit Suisse Securities (USA) LLC

Eleven Madison Avenue

New York, New York 10010-3629

Dear Sirs:

NorthWestern Corporation, a Delaware corporation (the "Company"), proposes to issue and sell to the several initial purchasers named in Schedule A hereto (collectively, the "Initial Purchasers"), upon the terms set forth in a purchase agreement, dated September 6, 2006 (the "Purchase Agreement"), among the Company and the Initial Purchasers, $150,000,000 aggregate principal amount of its 6.04% First Mortgage Bonds due 2016 (the "Initial Securities") The Initial Securities will be issued pursuant to the Mortgage and Deed of Trust, dated as of October 1, 1945, of the Company (as successor to NorthWestern Energy, L.L.C., in turn successor to The Montana Power Company) to The Bank of New York (as successor to Guaranty Trust Company of New York), as corporate trustee (the "Trustee"), and Ming Ryan (as indirect successor to Arthur E. Burke), as individual trustee, as amended and supplemented by various instruments including the supplemental indenture, to be dated the date hereof, establishing the terms of the Initial Securities, such Mortgage and Deed of Trust, as so amended and supplemented, being hereafter called the "Mortgage." As an inducement to the Initial Purchasers, the Company agrees with the Initial Purchasers, for the benefit of the holders of the Initial Securities (including, without limitation, the Initial Purchasers), the Exchange Securities (as defined below) and the Private Exchange Securities (as defined below) (collectively the "Holders"), as follows:

1.      Registered Exchange Offer. Unless not permitted by applicable law or applicable interpretations of the Staff of the Securities and Exchange Commission (the "Commission"), the Company shall, at its own cost, prepare and, not later than 180 days after (or if the 180th day is not a business day, the first business day thereafter) (such day being the "Exchange Offer Filing Deadline") the date of original issue of the Initial Securities (the "Issue Date"), file with the Commission a registration statement (the "Exchange Offer Registration Statement") on an appropriate form under the Securities Act of 1933, as amended (the "Securities Act"), with respect to a proposed offer (the "Registered Exchange Offer") to the Holders of Transfer Restricted Securities (as defined in Section 6 hereof), who are not prohibited by any law or policy of the Commission from participating in the Registered Exchange Offer, to issue and deliver to such Holders, in exchange for the Initial Securities, a like aggregate principal amount of debt securities (the "Exchange Securities") of the Company issued under the Mortgage and identical in all material respects to the Initial Securities (except for the transfer restrictions relating to the Initial Securities and the provisions relating to the matters described in Section 6 hereof) that are registered under the Securities Act. The Company shall use its commercially reasonable efforts to cause such Exchange Offer Registration Statement to become effective under the Securities Act within 270 days (or if the 270th day is not a business day, the first business day thereafter) (such day being the "Exchange Offer Effectiveness Deadline") after the Issue Date of the

Initial Securities and shall keep the Exchange Offer Registration Statement effective for not less than 30 days (or longer, if required by applicable law) after the date notice of the Registered Exchange Offer is mailed to the Holders (such period being called the "Exchange Offer Registration Period").

If the Company effects the Registered Exchange Offer, the Company will be entitled to close the Registered Exchange Offer 30 days after the commencement thereof provided that the Company has accepted all the Initial Securities theretofore validly tendered in accordance with the terms of the Registered Exchange Offer.

Following the declaration of the effectiveness of the Exchange Offer Registration Statement, the Company shall promptly commence the Registered Exchange Offer, it being the objective of such Registered Exchange Offer to enable each Holder of Transfer Restricted Securities (as defined in Section 6 hereof) electing to exchange the Initial Securities for Exchange Securities (assuming that such Holder is not an affiliate of the Company within the meaning of the Securities Act, acquires the Exchange Securities in the ordinary course of such Holder's business and has no arrangements with any person to participate in the distribution of the Exchange Securities and is not prohibited by any law or policy of the Commission from participating in the Registered Exchange Offer) to trade such Exchange Securities from and after their receipt without any limitations or restrictions under the Securities Act and without material restrictions under the securities laws of the several states of the United States.

The Company acknowledges that, pursuant to current interpretations by the Commission's staff of Section 5 of the Securities Act, in the absence of an applicable exemption therefrom, (i) each Holder which is a broker-dealer electing to exchange Initial Securities, acquired for its own account as a result of market making activities or other trading activities, for Exchange Securities (an "Exchanging Dealer"), is required to deliver a prospectus containing the information set forth in (a) Annex A hereto on the cover, (b) Annex B hereto in the "Exchange Offer Procedures" section and the "Purpose of the Exchange Offer" section, and (c) Annex C hereto in the "Plan of Distribution" section of such prospectus in connection with a sale of any such Exchange Securities received by such Exchanging Dealer pursuant to the Registered Exchange Offer and (ii) an Initial Purchaser that elects to sell Exchange Securities acquired in exchange for Initial Securities constituting any portion of an unsold allotment is required to deliver a prospectus containing the information required by Items 507 or 508 of Regulation S-K under the Securities Act, as applicable, in connection with such sale.

The Company shall use its commercially reasonable efforts to keep the Exchange Offer Registration Statement effective and to amend and supplement the prospectus contained therein, in order to permit such prospectus to be lawfully delivered by all persons subject to the prospectus delivery requirements of the Securities Act for such period of time as such persons must comply with such requirements in order to resell the Exchange Securities; provided, however, that (i) in the case where such prospectus and any amendment or supplement thereto must be delivered by an Exchanging Dealer or an Initial Purchaser, such period shall be the lesser of 180 days and the date on which all Exchanging Dealers and the Initial Purchasers have sold all Exchange Securities held by them (unless such period is extended pursuant to Section 3(j) below) and (ii) the Company shall make such prospectus and any amendment or supplement thereto, available to any broker-dealer for use in connection with any resale of any Exchange Securities for a period of not less than 90 days after the consummation of the Registered Exchange Offer.

If, upon consummation of the Registered Exchange Offer, any Initial Purchaser holds Initial Securities acquired by it as part of its initial distribution, the Company, simultaneously with the delivery of the Exchange Securities pursuant to the Registered Exchange Offer, shall issue and deliver to such Initial Purchaser upon the written request of such Initial Purchaser, in exchange (the "Private Exchange") for the Initial Securities held by such Initial Purchaser, a like principal amount of debt securities of the Company issued under the Mortgage and identical in all material respects (including the existence of restrictions on transfer under the Securities Act and the securities laws of the several states of the United States, but excluding provisions relating to the matters described in Section 6 hereof) to the Initial Securities (the "Private Exchange Securities"). The Initial Securities, the Exchange Securities and the Private Exchange Securities are herein collectively called the "Securities".

In connection with the Registered Exchange Offer, the Company shall:

(a)    mail to each Holder a copy of the prospectus forming part of the Exchange Offer Registration Statement, together with an appropriate letter of transmittal and related documents;

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(b)    keep the Registered Exchange Offer open for not less than 30 days (or longer, if required by applicable law) after the date notice thereof is mailed to the Holders;

(c)    utilize the services of a depositary for the Registered Exchange Offer with an address in the Borough of Manhattan, The City of New York, which may be the Trustee or an affiliate of the Trustee;

(d)    permit Holders to withdraw tendered Securities at any time prior to the close of business, New York time, on the last business day on which the Registered Exchange Offer shall remain open; and

(e)    otherwise comply with all applicable laws.

As soon as practicable after the close of the Registered Exchange Offer or the Private Exchange, as the case may be, the Company shall, directly or indirectly:

(x)    accept for exchange all the Securities validly tendered and not withdrawn pursuant to the Registered Exchange Offer and the Private Exchange;

(y)    deliver to the Trustee for cancellation all the Initial Securities so accepted for exchange; and

(z)    cause the Trustee to authenticate and deliver promptly to each Holder of the Initial Securities, Exchange Securities or Private Exchange Securities, as the case may be, equal in principal amount to the Initial Securities of such Holder so accepted for exchange.

The Mortgage will provide that the Exchange Securities will not be subject to the transfer restrictions set forth in the Mortgage and that all the Securities will vote and consent together on all matters as one class and that none of the Securities will have the right to vote or consent as a class separate from one another on any matter.

Interest on each Exchange Security and Private Exchange Security issued pursuant to the Registered Exchange Offer and in the Private Exchange will accrue from the last interest payment date on which interest was paid on the Initial Securities surrendered in exchange therefor or, if no interest has been paid on the Initial Securities, from the date of original issue of the Initial Securities.

Each Holder participating in the Registered Exchange Offer shall be required to represent to the Company that at the time of the consummation of the Registered Exchange Offer (i) any Exchange Securities received by such Holder will be acquired in the ordinary course of business, (ii) such Holder will have no arrangements or understanding with any person to participate in the distribution of the Securities or the Exchange Securities within the meaning of the Securities Act, (iii) such Holder is not an "affiliate," as defined in Rule 405 of the Securities Act, of the Company or if it is an affiliate, such Holder will comply with the registration and prospectus delivery requirements of the Securities Act to the extent applicable, (iv) if such Holder is not a broker-dealer, that it is not engaged in, and does not intend to engage in, the distribution of the Exchange Securities and (v) if such Holder is a broker-dealer, that it will receive Exchange Securities for its own account in exchange for Initial Securities that were acquired as a result of market-making activities or other trading activities and that it will be required to acknowledge that it will deliver a prospectus in connection with any resale of such Exchange Securities.

Notwithstanding any other provisions hereof, the Company will ensure that (i) any Exchange Offer Registration Statement and any amendment thereto and any prospectus forming part thereof and any supplement thereto complies in all material respects with the Securities Act and the rules and regulations thereunder, (ii) any Exchange Offer Registration Statement and any amendment thereto does not, when it becomes effective, contain an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading and (iii) any prospectus forming part of any Exchange Offer Registration Statement, and any supplement to such prospectus, does not include an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading.

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2.Shelf Registration. If, (i) because of any change in law or in applicable interpretations thereof by the staff of the Commission, the Company is not permitted to effect a Registered Exchange Offer, as contemplated by Section 1 hereof, as of the Exchange Offer Filing Deadline, (ii) the Registered Exchange Offer is not consummated by the 310th day following the Issue Date (such day being the "Exchange Offer Consummation Deadline"), (iii) any Initial Purchaser so requests in writing during the 20 business days following consummation of the Exchange Offer (such period being a "Shelf Registration Notice Period") with respect to the Initial Securities (or the Private Exchange Securities) not eligible to be exchanged for Exchange Securities in the Registered Exchange Offer and held by it following consummation of the Registered Exchange Offer or (iv) any Holder (other than an Exchanging Dealer) notifies the Company in writing during the Shelf Registration Notice Period that, based upon an opinion of counsel reasonably satisfactory to the Company, it was not eligible to participate in the Registered Exchange Offer or, if such Holder participates in the Registered Exchange Offer, such Holder will not receive freely tradeable Exchange Securities on the date of the exchange, the Company shall take the following actions:

(a)    The Company shall, at its cost, as promptly as practicable (but in no event more than 90 days after the Exchange Offer Filing Deadline (in the case of (i) above), the Exchange Offer Consummation Deadline (in the case of (ii) above) or the expiration of the Shelf Registration Notice Period (in the case of (iii) and (iv) above) (each such day being a "Shelf Registration Filing Deadline")), file with the Commission and thereafter shall use its commercially reasonable efforts to cause to be declared effective (unless it becomes effective automatically upon filing) a registration statement (the "Shelf Registration Statement" and, together with the Exchange Offer Registration Statement, a "Registration Statement") on an appropriate form under the Securities Act relating to the offer and sale of the Transfer Restricted Securities (as defined in Section 6 hereof) by the Holders thereof from time to time in accordance with the methods of distribution set forth in the Shelf Registration Statement and Rule 415 under the Securities Act (hereinafter, the "Shelf Registration"); provided, however, that no Holder (other than an Initial Purchaser) shall be entitled to have the Securities held by it covered by such Shelf Registration Statement unless such Holder agrees in writing to be bound by all the provisions of this Agreement applicable to such Holder; provided, further, that, to the extent the Company was obligated to file a Shelf Registration Statement solely because it did not consummate the Registered Exchange Offer in a timely fashion by the Exchange Offer Consummation Deadline as described in (ii) above, the Company need not file or continue the filing of any such Shelf Registration Statement if the Exchange Offer is consummated subsequent to the Exchange Offer Consummation Deadline (it being understood that, to the extent the Company is or was obligated to file a Shelf Registration Statement for any other purpose, such obligation will remain binding).

(b)    The Company shall use its commercially reasonable efforts to keep the Shelf Registration Statement continuously effective in order to permit the prospectus included therein to be lawfully delivered by the Holders of the relevant Securities, for a period of two years (or for such longer period if extended pursuant to Section 3(j) below) from the date of its effectiveness or such shorter period that will terminate when all the Securities covered by the Shelf Registration Statement (i) have been sold pursuant thereto or (ii) are distributed to the public pursuant to Rule 144 under the Securities Act, or any successor rule thereof, are saleable pursuant to Rule 144(k) under the Securities Act, or any successor rule thereof, or are otherwise no longer restricted securities (as defined in Rule 144 under the Securities Act, or any successor rule thereof) (the "Shelf Registration Termination Date"). The Company shall be deemed not to have used its commercially reasonable efforts to keep the Shelf Registration Statement effective during the requisite period if it voluntarily takes any action that would result in Holders of Securities covered thereby not being able to offer and sell such Securities during that period, unless (i) such action is required by applicable law, (ii) the Company complies with this Agreement or (iii) such action is taken by the Company in good faith and for valid business reasons (not including avoidance by the Company of its obligations hereunder), including the acquisition or divestiture of assets, so long as such action does not result in a lapse in the effectiveness of the Shelf Registration Statement of more than 45 consecutive days or 60 days within a twelve month period and the Company promptly thereafter complies with the requirements of Section 3(j) hereof, if applicable.

(c)     Notwithstanding any other provisions of this Agreement to the contrary, the Company shall cause the Shelf Registration Statement and the related prospectus and any amendment or supplement thereto, as of its respective effective date, (i) to comply in all material respects with the applicable requirements of the Securities Act and the rules and regulations of the Commission and (ii) not to contain

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any untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary in order to make the statements therein (in the case of any prospectus, in light of the circumstances under which they were made), not misleading.

No Holder of Transfer Restricted Securities may include any of its Transfer Restricted Securities in any Shelf Registration Statement pursuant to this Agreement unless and until such Holder furnished to the Company in writing, within 10 days after receipt of a written request therefor, the information specified in Item 507 or 508 of Regulation S-K, as applicable, of the Securities Act for use in connection with any Shelf Registration Statement or Prospectus or preliminary prospectus included therein. Each selling Holder agrees to promptly furnish additional information required to be disclosed in order to make the information previously furnished to the Company by such Holder not materially misleading.

3.Registration Procedures. In connection with any Shelf Registration contemplated by Section 2 hereof and, to the extent applicable, any Registered Exchange Offer contemplated by Section 1 hereof, the following provisions shall apply:

(a)    The Company shall (i) furnish to each Initial Purchaser, prior to the filing thereof with the Commission, a copy of the Registration Statement and each amendment thereof and each supplement, if any, to the prospectus included therein and, in the event that an Initial Purchaser (with respect to any portion of an unsold allotment from the original offering) is participating in the Registered Exchange Offer or the Shelf Registration Statement, the Company shall use its commercially reasonable efforts to reflect in each such document, when so filed with the Commission, such comments as such Initial Purchaser reasonably may propose; (ii) include the information set forth in Annex A hereto on the cover, in Annex B hereto in the "Exchange Offer Procedures" section and the "Purpose of the Exchange Offer" section and in Annex C hereto in the "Plan of Distribution" section of the prospectus forming a part of the Exchange Offer Registration Statement and include the information set forth in Annex D hereto in the Letter of Transmittal delivered pursuant to the Registered Exchange Offer; (iii) if requested by an Initial Purchaser, include the information required by Items 507 or 508 of Regulation S-K under the Securities Act, as applicable, in the prospectus forming a part of the Exchange Offer Registration Statement; (iv) include within the prospectus contained in the Exchange Offer Registration Statement a section entitled "Plan of Distribution," reasonably acceptable to the Initial Purchasers, which shall contain a summary statement of the positions taken or policies made by the staff of the Commission with respect to the potential "underwriter" status of any broker-dealer that is the beneficial owner (as defined in Rule 13d-3 under the Securities Exchange Act of 1934, as amended (the "Exchange Act")) of Exchange Securities received by such broker-dealer in the Registered Exchange Offer (a "Participating Broker-Dealer"), whether such positions or policies have been publicly disseminated by the staff of the Commission or such positions or policies, in the reasonable judgment of the Initial Purchasers based upon advice of counsel (which may be in-house counsel), represent the prevailing views of the staff of the Commission; and (v) in the case of a Shelf Registration Statement, include in the prospectus included in the Shelf Registration Statement (or, if permitted by Commission Rule 430B(b), in a prospectus supplement that becomes a part thereof pursuant to Commission Rule 430B(f)) that is delivered to any Holder pursuant to Section 3(d) and (f), the names of the Holders, who propose to sell Securities pursuant to the Shelf Registration Statement, as selling securityholders.

(b)    The Company shall give written notice to the Initial Purchasers, the Holders of the Securities and any Participating Broker-Dealer from whom the Company has received prior written notice that it will be a Participating Broker-Dealer in the Registered Exchange Offer (which notice pursuant to clauses (ii)-(v) hereof shall be accompanied by an instruction to suspend the use of the prospectus until the requisite changes have been made):

(i)     when the Registration Statement or any amendment thereto has been filed with the Commission and when the Registration Statement or any post-effective amendment thereto has become effective;

(ii)    of any request by the Commission for amendments or supplements to the Registration Statement or the prospectus included therein or for additional information;

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(iii)   of the issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement or the initiation of any proceedings for that purpose, of the issuance by the Commission of a notification of objection to the use of the form on which the Registration Statement has been filed, and of the happening of any event that causes the Company to become an "ineligible issuer," as defined in Commission Rule 405;

(iv)   of the receipt by the Company or its legal counsel of any notification with respect to the suspension of the qualification of the Securities for sale in any jurisdiction or the initiation or threatening of any proceeding for such purpose; and

(v)    of the happening of any event that requires the Company to make changes in the Registration Statement or the prospectus in order that the Registration Statement or the prospectus do not contain an untrue statement of a material fact nor omit to state a material fact required to be stated therein or necessary to make the statements therein (in the case of the prospectus, in light of the circumstances under which they were made) not misleading.

(c)    The Company shall use its commercially reasonable effort to obtain the withdrawal at the earliest possible time, of any order suspending the effectiveness of the Registration Statement.

(d)    The Company shall furnish to each Holder of Securities included within the coverage of the Shelf Registration, without charge, at least one copy of the Shelf Registration Statement and any post-effective amendment or supplement thereto, including financial statements and schedules, and, if the Holder so requests in writing, all exhibits thereto (including those, if any, incorporated by reference). The Company shall not, without the prior consent of the Initial Purchasers, make any offer relating to the Securities that would constitute a "free writing prospectus," as defined in Commission Rule 405.

(e)    The Company shall deliver to each Exchanging Dealer and each Initial Purchaser, and to any other Holder who so requests, without charge, at least one copy of the Exchange Offer Registration Statement and any post-effective amendment thereto, including financial statements and schedules, and, if any Initial Purchaser or any such Holder requests, all exhibits thereto (including those incorporated by reference).

(f)     The Company shall, during the Shelf Registration Period, deliver to each Holder of Securities included within the coverage of the Shelf Registration, without charge, as many copies of the prospectus (including each preliminary prospectus) included in the Shelf Registration Statement and any amendment or supplement thereto as such person may reasonably request. The Company consents, subject to the provisions of this Agreement, to the use of the prospectus or any amendment or supplement thereto by each of the selling Holders of the Securities in connection with the offering and sale of the Securities covered by the prospectus, or any amendment or supplement thereto, included in the Shelf Registration Statement.

(g)    The Company shall deliver to each Initial Purchaser, any Exchanging Dealer, any Participating Broker-Dealer and such other persons required to deliver a prospectus following the Registered Exchange Offer, without charge, as many copies of the final prospectus included in the Exchange Offer Registration Statement and any amendment or supplement thereto as such persons may reasonably request. The Company consents, subject to the provisions of this Agreement, to the use of the prospectus or any amendment or supplement thereto by any Initial Purchaser, if necessary, any Participating Broker-Dealer and such other persons required to deliver a prospectus following the Registered Exchange Offer in connection with the offering and sale of the Exchange Securities covered by the prospectus, or any amendment or supplement thereto, included in such Exchange Offer Registration Statement.

(h)    Prior to any public offering of the Securities, pursuant to any Registration Statement, the Company shall use its commercially reasonable effort to register or qualify or cooperate with the Holders of the Securities included therein and their respective counsel in connection with the registration or qualification of the Securities for offer and sale under the securities or "blue sky" laws of such states of the United States as any Holder of the Securities reasonably requests in writing and do any and all other acts or

6

things necessary or advisable to enable the offer and sale in such jurisdictions of the Securities covered by such Registration Statement; provided, however, that the Company shall not be required to (i) qualify generally to do business or as a securities dealer in any jurisdiction where it is not then so qualified or (ii) take any action which would subject it to general service of process or to taxation in any jurisdiction where it is not then so subject.

(i)     The Company shall cooperate with the Holders of the Securities to facilitate the timely preparation and delivery of certificates representing the Securities to be sold pursuant to any Registration Statement free of any restrictive legends (to the extent permitted by the Securities Act) and in such denominations and registered in such names as the Holders may request a reasonable period of time prior to sales of the Securities pursuant to such Registration Statement.

(j)     Upon the occurrence of any event contemplated by paragraphs (ii) through (v) of Section 3(b) above during the period for which the Company is required to maintain an effective Registration Statement, the Company shall promptly prepare and file a post-effective amendment to the Registration Statement or a supplement to the related prospectus and any other required document so that, as thereafter delivered to Holders of the Securities or purchasers of Securities, the prospectus will not contain an untrue statement of a material fact or omit to state any material fact required to be stated therein or necessary to make the statements therein (in the case of any prospectus, in light of the circumstances under which they were made) not misleading. If the Company notifies the Initial Purchasers, the Holders of the Securities and any known Participating Broker-Dealer in accordance with paragraphs (ii) through (v) of Section 3(b) above to suspend the use of the prospectus until the requisite changes to the prospectus have been made, then the Initial Purchasers, the Holders of the Securities and any such Participating Broker-Dealers shall suspend use of such prospectus, and the period of effectiveness of the Shelf Registration Statement provided for in Section 2(b) above and the Exchange Offer Registration Statement provided for in Section 1 above shall each be extended by the number of days from and including the date of the giving of such notice to and including the date when the Initial Purchasers, the Holders of the Securities and any known Participating Broker-Dealer shall have received such amended or supplemented prospectus pursuant to this Section 3(j). Each Holder receiving a suspension notice shall either (i) destroy any prospectuses, other than permanent file copies, then in such Holder’s possession which have been replaced by the Company with more recently dated prospectuses or (ii) deliver to the Company (at the Company’s expense) all copies, other than permanent file copies, then in such Holder’s possession of the prospectus covering such Transfer Restricted Securities that was current at the time of receipt of the suspension notice. During the period during which the Company is required to maintain an effective Shelf Registration Statement pursuant to this Agreement, the Company will prior to the three-year expiration of that Shelf Registration Statement file, and use its commercially reasonable efforts to cause to be declared effective (unless it becomes effective automatically upon filing) within a period that avoids any interruption in the ability of Holders of Securities covered by the expiring Shelf Registration Statement to make registered dispositions, a new registration statement relating to the Securities, which shall be deemed the "Shelf Registration Statement" for purposes of this Agreement.

(k)    Not later than the effective date of the applicable Registration Statement, the Company will provide a CUSIP number for the Initial Securities, the Exchange Securities or the Private Exchange Securities, as the case may be, and provide the applicable trustee with printed certificates for the Initial Securities, the Exchange Securities or the Private Exchange Securities, as the case may be, in a form eligible for deposit with The Depository Trust Company.

(l)     The Company will comply with all rules and regulations of the Commission to the extent and so long as they are applicable to the Registered Exchange Offer or the Shelf Registration and will make generally available to its security holders (or otherwise provide in accordance with Section 11(a) of the Securities Act) an earnings statement (which need not be audited) satisfying the provisions of Section 11(a) of the Securities Act, no later than 45 days after the end of a 12-month period (or 90 days, if such period is a fiscal year) beginning with the first month of the Company's first fiscal quarter commencing after the effective date of the Registration Statement, which statement shall cover such 12-month period.

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(m)   The Company shall cause the Mortgage to be qualified under the Trust Indenture Act of 1939, as amended, in a timely manner and containing such changes, if any, as shall be necessary for such qualification. In the event that such qualification would require the appointment of a new trustee under the Mortgage, the Company shall appoint a new trustee thereunder pursuant to the applicable provisions of the Mortgage.

(n)    The Company may require each Holder of Securities to be sold pursuant to the Shelf Registration Statement to furnish to the Company such information regarding the Holder and the distribution of the Securities as the Company may from time to time reasonably require for inclusion in the Shelf Registration Statement, and the Company may exclude from such registration the Securities of any Holder that unreasonably fails to furnish such information within a reasonable time after receiving such request.

(o)    In the case of any Shelf Registration, the Company shall enter into such customary agreements (including, if requested, an underwriting agreement in customary form) and take all such other action, if any, as any Holder of the Securities shall reasonably request in order to facilitate the disposition of the Securities pursuant to any Shelf Registration.

(p)    In the case of any Shelf Registration, the Company shall (i) make reasonably available for inspection by the Holders of the Securities, any underwriter participating in any disposition pursuant to the Shelf Registration Statement and any attorney, accountant or other agent retained by the Holders of the Securities or any such underwriter all relevant financial and other records, pertinent corporate documents and properties of the Company and (ii) cause the Company's officers, directors, employees, accountants and auditors to supply all relevant information reasonably requested by the Holders of the Securities or any such underwriter, attorney, accountant or agent in connection with the Shelf Registration Statement, in each case, as shall be reasonably necessary to enable such persons, to conduct a reasonable investigation within the meaning of Section 11 of the Securities Act; provided, however, that the foregoing inspection and information gathering shall be coordinated on behalf of the Initial Purchasers by you and on behalf of the other parties, by one counsel designated by and on behalf of such other parties as described in Section 4 hereof; provided, however, that any non-public information shall be kept confidential by the Holders or any underwriter, attorney, accountant or agent, unless such disclosure is required by law or becomes available to the public generally through a third party without an accompanying obligation of confidentiality other than as a result of a disclosure of such information by any such Holder, underwriter, attorney, accountant or agent.

(q)    In the case of any Shelf Registration, the Company, if requested by any Holder of Securities covered thereby, shall cause (i) its counsel (which may be in-house counsel) to deliver an opinion and updates thereof relating to the Securities in customary form addressed to such Holders and the managing underwriters, if any, thereof and dated, in the case of the initial opinion, the effective date of such Shelf Registration Statement (it being agreed that the matters to be covered by such opinion shall include, without limitation, the due incorporation and good standing of the Company and its subsidiaries; the qualification of the Company and its subsidiaries to transact business as foreign corporations; the due authorization, execution and delivery of the relevant agreement of the type referred to in Section 3(o) hereof; the due authorization, execution, authentication and issuance, and the validity and enforceability, of the applicable Securities; the absence of material legal or governmental proceedings involving the Company and its subsidiaries; the absence of governmental approvals required to be obtained in connection with the Shelf Registration Statement, the offering and sale of the applicable Securities, or any agreement of the type referred to in Section 3(o) hereof; the compliance as to form of such Shelf Registration Statement and any documents incorporated by reference therein and of the Mortgage with the requirements of the Securities Act and the Trust Indenture Act, respectively; as of the date of the opinion and as of the effective date of the Shelf Registration Statement or most recent post-effective amendment thereto or most recent prospectus supplement thereto that is deemed to establish a new effective date, as the case may be, the absence from such Shelf Registration Statement and the prospectus and any prospectus supplement included therein, as then amended or supplemented and including any documents incorporated by reference therein, of an untrue statement of a material fact or the omission to state therein a material fact required to be stated therein or necessary to make the statements therein not misleading; and as of an applicable time

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identified by such Holders or managing underwriters, the absence from the prospectus included in the Registration Statement, as amended or supplemented at such applicable time and including any documents incorporated by reference therein, taken together with any other documents identified by such Holders or managing underwriters, of an untrue statement of a material fact or the omission to state therein a material fact required to be stated therein or necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading; (ii) its officers to execute and deliver all customary documents and certificates and updates thereof reasonably requested by any underwriters of the applicable Securities and (iii) its independent registered public accounting firm to provide to the selling Holders of the applicable Securities and any underwriter therefor a comfort letter in customary form and covering matters of the type customarily covered in comfort letters in connection with primary underwritten offerings, subject to receipt of appropriate documentation as contemplated, and only if permitted, by Statement of Auditing Standards No. 72.

(r)    In the case of the Registered Exchange Offer, if reasonably requested by any Initial Purchaser or any known Participating Broker-Dealer, the Company shall cause (i) its counsel to deliver to such Initial Purchaser or such Participating Broker-Dealer signed opinions in the forms set forth in Sections 7(c) and (d) of the Purchase Agreement with such changes as are customary in connection with the preparation of a Registration Statement and (ii) its independent registered public accounting firm to deliver to such Initial Purchaser or such Participating Broker-Dealer a comfort letter, in customary form, meeting the requirements as to the substance thereof as set forth in Section 7(a) of the Purchase Agreement, with appropriate date changes.

(s)    If a Registered Exchange Offer or a Private Exchange is to be consummated, upon delivery of the Initial Securities by Holders to the Company (or to such other Person as directed by the Company) in exchange for the Exchange Securities or the Private Exchange Securities, as the case may be, the Company shall mark, or caused to be marked, on the Initial Securities so exchanged that such Initial Securities are being canceled in exchange for the Exchange Securities or the Private Exchange Securities, as the case may be; in no event shall the Initial Securities be marked as paid or otherwise satisfied.

(t)     The Company will use its commercially reasonable efforts to (a) if the Initial Securities have been rated prior to the initial sale of such Initial Securities, confirm such ratings will apply to the Securities covered by a Registration Statement, or (b) if the Initial Securities were not previously rated, cause the Securities covered by a Registration Statement to be rated with up to two appropriate rating agencies, if so requested by Holders of a majority in aggregate principal amount of Securities covered by such Registration Statement, or by the managing underwriters, if any, in the case of a Shelf Registration for an underwritten offering.

(u)    In the event that any broker-dealer registered under the Exchange Act shall underwrite any Securities or participate as a member of an underwriting syndicate or selling group or "assist in the distribution" (within the meaning of the Conduct Rules (the "Rules") of the National Association of Securities Dealers, Inc. ("NASD")) thereof, whether as a Holder of such Securities or as an underwriter, a placement or sales agent or a broker or dealer in respect thereof, or otherwise, the Company will assist such broker-dealer in complying with the requirements of such Rules, including, without limitation, by (i) if such Rules, including Rule 2720, shall so require, engaging a "qualified independent underwriter" (as defined in Rule 2720) to participate in the preparation of the Registration Statement relating to such Securities, to exercise usual standards of due diligence in respect thereto and, if any portion of the offering contemplated by such Registration Statement is an underwritten offering or is made through a placement or sales agent, to recommend the yield of such Securities, (ii) indemnifying any such qualified independent underwriter to the extent of the indemnification of underwriters provided in Section 5 hereof and (iii) providing such information to such broker-dealer as may be required in order for such broker-dealer to comply with the requirements of the Rules.

(v)    The Company shall use its commercially reasonable efforts to take all other steps necessary to effect the registration of the Securities covered by a Registration Statement contemplated hereby.

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4.Registration Expenses. The Company shall bear all fees and expenses incurred in connection with the performance of its obligations under Sections 1 through 3 hereof and shall reimburse the Initial Purchasers and the Holders of Transfer Restricted Securities who are tendering Initial Securities in the Registered Exchange Offer and/or selling or reselling Securities pursuant to the "Plan of Distribution" contained in the Exchange Offer Registration Statement or the Shelf Registration Statement, as applicable, for the reasonable fees and expenses, if any, of not more than one counsel, who shall be Dewey Ballantine LLP unless another firm shall be chosen by the Holders of a majority in principal amount of the Initial Securities covered thereby, whether or not the Registered Exchange Offer or a Shelf Registration is filed or becomes effective.

5.Indemnification. (a) The Company agrees to indemnify and hold harmless each Holder of the Securities, any Participating Broker-Dealer and each person, if any, who controls such Holder or such Participating Broker-Dealer within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act (each Holder, any Participating Broker-Dealer and such controlling persons are referred to collectively as the "Indemnified Parties") from and against any losses, claims, damages or liabilities, joint or several, or any actions in respect thereof (including, but not limited to, any losses, claims, damages, liabilities or actions relating to purchases and sales of the Securities) to which each Indemnified Party may become subject under the Securities Act, the Exchange Act or otherwise, insofar as such losses, claims, damages, liabilities or actions arise out of or are based upon any untrue statement or alleged untrue statement of a material fact contained in a Registration Statement or prospectus or in any amendment or supplement thereto or in any preliminary prospectus or "issuer free writing prospectus, " as defined in Commission Rule 433 ("Issuer FWP"), relating to a Shelf Registration, or arise out of, or are based upon, the omission or alleged omission to state therein a material fact required to be stated therein or necessary in order to make the statements therein (in the case of any prospectus, in light of the circumstances under which they were made) not misleading, and shall reimburse, as incurred, the Indemnified Parties for any legal or other expenses reasonably incurred by them in connection with investigating or defending any such loss, claim, damage, liability or action in respect thereof; provided, however, that the Company shall not be liable in any such case to the extent that such loss, claim, damage or liability arises out of or is based upon any untrue statement or alleged untrue statement or omission or alleged omission made in a Registration Statement or prospectus or in any amendment or supplement thereto or in any preliminary prospectus or Issuer FWP relating to a Shelf Registration in reliance upon and in conformity with written information pertaining to such Holder and furnished to the Company by or on behalf of such Holder specifically for inclusion therein; provided further, however, that this indemnity agreement will be in addition to any liability which the Company may otherwise have to such Indemnified Party. The Company shall also indemnify underwriters, their officers and directors and each person who controls such underwriters within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act to the same extent as provided above with respect to the indemnification of the Holders of the Securities if requested by such Holders in the case of a Shelf Registration for an underwritten offering; provided, to the extent such Holders so request indemnification for the underwriters, that each underwriter agrees to indemnify, severally and not jointly, the Company, its directors and officers and each person, if any, who controls the Company within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act to the same extent as provided in Section (b) below with respect to written information pertaining to such underwriter and furnished to the Company by or on behalf of such underwriter specifically for inclusion in such Shelf Registration Statement or prospectus.

(b)    Each Holder of the Securities, severally and not jointly, will indemnify and hold harmless the Company and each person, if any, who controls the Company within the meaning of Section 15 the Securities Act or Section 20 of the Exchange Act from and against any losses, claims, damages or liabilities or any actions in respect thereof, to which the Company or any such controlling person may become subject under the Securities Act, the Exchange Act or otherwise, insofar as such losses, claims, damages, liabilities or actions arise out of or are based upon any untrue statement or alleged untrue statement of a material fact contained in a Registration Statement or prospectus or in any amendment or supplement thereto or in any preliminary prospectus or Issuer FWP relating to a Shelf Registration, or arise out of or are based upon the omission or alleged omission to state therein a material fact required to be stated therein or necessary in order to make the statements therein (in the case of any prospectus, in light of the circumstances under which they were made) not misleading, but in each case only to the extent that the untrue statement or omission or alleged untrue statement or omission was made in reliance upon and in conformity with written information pertaining to such Holder and furnished to the Company by or on behalf of such Holder specifically for inclusion therein; and, subject to the limitation set forth immediately preceding this clause, shall reimburse, as incurred, the Company for any legal or other expenses reasonably incurred by the Company or any such controlling person in connection with investigating or defending any loss, claim, damage, liability or action in

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respect thereof. This indemnity agreement will be in addition to any liability which such Holder may otherwise have to the Company or any of its controlling persons.

(c)    Promptly after receipt by an indemnified party under this Section 5 of notice of the commencement of any action or proceeding (including a governmental investigation), such indemnified party will, if a claim in respect thereof is to be made against the indemnifying party under this Section 5, notify the indemnifying party of the commencement thereof; but the failure to notify the indemnifying party shall not relieve the indemnifying party from any liability that it may have under subsection (a) or (b) above except to the extent that it has been materially prejudiced by such failure; and provided further that the failure to notify the indemnifying party shall not relieve it from any liability that it may have to an indemnified party otherwise than under subsection (a) or (b) above. In case any such action is brought against any indemnified party, and it notifies the indemnifying party of the commencement thereof, the indemnifying party will be entitled to participate therein and, to the extent that it may wish, jointly with any other indemnifying party similarly notified, to assume the defense thereof, with counsel reasonably satisfactory to such indemnified party (who shall not, except with the consent of the indemnified party, be counsel to the indemnifying party), and after notice from the indemnifying party to such indemnified party of its election so to assume the defense thereof the indemnifying party will not be liable to such indemnified party under this Section 5 for any legal or other expenses, other than reasonable costs of investigation, subsequently incurred by such indemnified party in connection with the defense thereof. No indemnifying party shall, without the prior written consent of the indemnified party, effect any settlement of any pending or threatened action in respect of which any indemnified party is or could have been a party and indemnity could have been sought hereunder by such indemnified party unless such settlement (i) includes an unconditional release of such indemnified party from all liability on any claims that are the subject matter of such action, and (ii) does not include a statement as to or an admission of fault, culpability or a failure to act by or on behalf of any indemnified party.

(d)    If the indemnification provided for in this Section 5 is unavailable or insufficient to hold harmless an indemnified party under subsections (a) or (b) above, then each indemnifying party shall contribute to the amount paid or payable by such indemnified party as a result of the losses, claims, damages or liabilities (or actions in respect thereof) referred to in subsection (a) or (b) above (i) in such proportion as is appropriate to reflect the relative benefits received by the indemnifying party or parties on the one hand and the indemnified party on the other from the exchange of the Securities, pursuant to the Registered Exchange Offer, or (ii) if the allocation provided by the foregoing clause (i) is not permitted by applicable law, in such proportion as is appropriate to reflect not only the relative benefits referred to in clause (i) above but also the relative fault of the indemnifying party or parties on the one hand and the indemnified party on the other in connection with the statements or omissions that resulted in such losses, claims, damages or liabilities (or actions in respect thereof) as well as any other relevant equitable considerations. The relative fault of the parties shall be determined by reference to, among other things, whether the untrue or alleged untrue statement of a material fact or the omission or alleged omission to state a material fact relates to information supplied by the Company on the one hand or such Holder or such other indemnified party, as the case may be, on the other, and the parties' relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission. The amount paid by an indemnified party as a result of the losses, claims, damages or liabilities referred to in the first sentence of this subsection (d) shall be deemed to include any legal or other expenses reasonably incurred by such indemnified party in connection with investigating or defending any action or claim which is the subject of this subsection (d). Notwithstanding any other provision of this Section 5(d), the Holders of the Securities shall not be required to contribute any amount in excess of the amount by which the net proceeds received by such Holders from the sale of the Securities pursuant to a Registration Statement exceeds the amount of damages which such Holders have otherwise been required to pay by reason of such untrue or alleged untrue statement or omission or alleged omission. No person guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of the Securities Act) shall be entitled to contribution from any person who was not guilty of such fraudulent misrepresentation. For purposes of this paragraph (d), each person, if any, who controls such indemnified party within the meaning of the Securities Act or the Exchange Act shall have the same rights to contribution as such indemnified party and each person, if any, who controls the Company within the meaning of the Securities Act or the Exchange Act shall have the same rights to contribution as the Company.

(e)    The agreements contained in this Section 5 shall survive the sale of the Securities pursuant to a Registration Statement and shall remain in full force and effect, regardless of any termination or cancellation of this Agreement or any investigation made by or on behalf of any indemnified party.

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6.Additional Interest Under Certain Circumstances. (a) Additional interest (the "Additional Interest") with respect to the Initial Securities shall be assessed as follows if any of the following events occur (each such event in clauses (i) through (v) below a "Registration Default"):

(i)     If on or prior to the Exchange Offer Filing Deadline, the Exchange Offer Registration Statement has not been filed with the Commission;

(ii)    If on or prior to the Shelf Registration Filing Deadline, a Shelf Registration Statement has not been filed with the Commission;

(iii)  If on or prior to the Exchange Offer Consummation Deadline, the Registered Exchange Offer is not consummated;

(iv)   If on or prior to 90 days following the Shelf Registration Filing Deadline (such day being the "Shelf Registration Effectiveness Deadline") in the event a Shelf Registration is required in lieu of the Registered Exchange Offer pursuant to Section 2 hereof, the Shelf Registration Statement has not become effective; or

(v)    If after either the Exchange Offer Registration Statement or the Shelf Registration Statement becomes effective (A) such Registration Statement thereafter ceases to be effective; or (B) such Registration Statement or the related prospectus ceases to be usable (except as permitted in paragraph (b)) in connection with resales of Transfer Restricted Securities during any periods after the Exchange Offer Effectiveness Deadline or Shelf Registration Effectiveness Deadline, as the case may be, but prior to the consummation of the Exchange Offer or the Shelf Registration Termination Date, as the case may be, because either (1) any event occurs as a result of which the related prospectus forming part of such Registration Statement would include any untrue statement of a material fact or omit to state any material fact necessary to make the statements therein, in the light of the circumstances under which they were made, not misleading, (2) it shall be necessary to amend such Registration Statement or supplement the related prospectus, to comply with the Securities Act or the Exchange Act or the respective rules thereunder, or (3) such Registration Statement is a Shelf Registration Statement that has expired before a replacement Shelf Registration Statement has become effective.

Additional Interest shall accrue on the Initial Securities over and above the interest set forth in the title of the Securities from and including the date on which any such Registration Default shall occur to but excluding the date on which all such Registration Defaults have been cured, at a rate of 0.25% per annum (the "Additional Interest Rate") for the first 90-day period immediately following the occurrence of such Registration Default. The Additional Interest Rate shall increase by an additional 0.25% per annum with respect to each subsequent 90-day period until all Registration Defaults have been cured, up to a maximum Additional Interest Rate of 1.0% per annum.

(b)    A Registration Default referred to in Section 6(a)(v)(B) hereof shall be deemed not to have occurred and be continuing in relation to a Shelf Registration Statement or the related prospectus if (i) such Registration Default has occurred solely as a result of (x) the filing of a post-effective amendment to such Shelf Registration Statement to incorporate annual audited financial information with respect to the Company where such post-effective amendment is not yet effective and needs to be declared effective to permit Holders to use the related prospectus or (y) other material events, with respect to the Company that would need to be described in such Shelf Registration Statement or the related prospectus and (ii) in the case of clause (y), the Company is proceeding promptly and in good faith to amend or supplement such Shelf Registration Statement and related prospectus to describe such events; provided, however, that in any case if such Registration Default occurs for a continuous period in excess of 60 days, Additional Interest shall be payable in accordance with the above paragraph from the day such Registration Default occurs until such Registration Default is cured.

(c)    Any amounts of Additional Interest due pursuant to clause (i), (ii), (iii), (iv) or (v) of Section 6(a) above will be payable in cash on the regular interest payment dates with respect to the Initial Securities. The amount of Additional Interest will be determined by multiplying the Additional Interest rate by the principal amount

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of the Initial Securities, multiplied by a fraction, the numerator of which is the number of days such Additional Interest rate was applicable during such period (determined on the basis of a 360-day year comprised of twelve 30-day months), and the denominator of which is 360.

(d)    "Transfer Restricted Securities" means each Security until the earlier to occur of (i) the date on which such Transfer Restricted Security has been exchanged by a person other than a broker-dealer for a freely transferable Exchange Security in the Registered Exchange Offer, (ii) following the exchange by a broker-dealer in the Registered Exchange Offer of an Initial Security for an Exchange Security, the date on which such Exchange Security is sold to a purchaser who receives from such broker-dealer on or prior to the date of such sale a copy of the prospectus contained in the Exchange Offer Registration Statement, (iii) the date on which such Initial Security has been effectively registered under the Securities Act and disposed of in accordance with the Shelf Registration Statement or (iv) the date on which such Initial Security is distributed to the public pursuant to Rule 144 under the Securities Act or is saleable pursuant to Rule 144(k) under the Securities Act.

7.Rules 144 and 144A. The Company shall use its commercially reasonable efforts to file the reports required to be filed by it under the Securities Act and the Exchange Act in a timely manner and, if at any time the Company is not required to file such reports, it will, upon the request of any Holder of Initial Securities, make publicly available other information so long as necessary to permit sales of their securities pursuant to Rules 144 and 144A. The Company covenants that it will take such further action as any Holder of Initial Securities may reasonably request, all to the extent required from time to time to enable such Holder to sell Initial Securities without registration under the Securities Act within the limitation of the exemptions provided by Rules 144 and 144A (including the requirements of Rule 144A(d)(4)). The Company will provide a copy of this Agreement to prospective purchasers of Initial Securities identified to the Company by the Initial Purchasers upon request. Upon the request of any Holder of Initial Securities, the Company shall deliver to such Holder a written statement as to whether it has complied with such requirements. Notwithstanding the foregoing, nothing in this Section 7 shall be deemed to require the Company to register any of its securities pursuant to the Exchange Act.

8.Underwritten Registrations. If any of the Transfer Restricted Securities covered by any Shelf Registration are to be sold in an underwritten offering, the investment banker or investment bankers and manager or managers that will administer the offering ("Managing Underwriters") will be selected by the Holders of a majority in aggregate principal amount of such Transfer Restricted Securities to be included in such offering and approved by the Company.

No person may participate in any underwritten registration hereunder unless such person (i) agrees to sell such person's Transfer Restricted Securities on the basis reasonably provided in any underwriting arrangements approved by the persons entitled hereunder to approve such arrangements and (ii) completes and executes all questionnaires, powers of attorney, indemnities, underwriting agreements and other documents reasonably required under the terms of such underwriting arrangements.

9. Miscellaneous.

(a)Amendments and Waivers. The provisions of this Agreement may not be amended, modified or supplemented, and waivers or consents to departures from the provisions hereof may not be given, except by the Company and the written consent of the Holders of a majority in principal amount of the Securities affected by such amendment, modification, supplement, waiver or consents.

(b)Notices. All notices and other communications provided for or permitted hereunder shall be made in writing by hand delivery, first-class mail, facsimile transmission, or air courier which guarantees overnight delivery:

(1) if to a Holder of the Securities, at the most current address given by such Holder to the Company.

(2) if to the Initial Purchasers;

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Credit Suisse Securities (USA) LLC

Eleven Madison Avenue

New York, NY 10010-3629

Fax No.: (212) 325-8278

Attention: LCD-IBD Group

Deutsche Bank Securities Inc.

60 Wall Street

New York, NY 10005

Fax No.: (212) 797-2202

Attention: Debt Capital Markets, Syndicate Desk

with a copy to:

Dewey Ballantine LLP

1301 Avenue of the Americas

New York, NY 10019

Fax No.: (212) 259-6333

Attention: Peter K. O’Brien

(3) if to the Company, at its address as follows:

NorthWestern Corporation

125 S. Dakota Avenue

Sioux Falls, SD 57104-6403

Fax No.: (605) 978-2840

Attention: Treasurer

with a copy to:

Leonard, Street and Deinard, Professional Association

150 South Fifth Street, Suite 2300

Fax No.: (612) 810-4191

Attention: Tammie S. Ptacek

All such notices and communications shall be deemed to have been duly given: at the time delivered by hand, if personally delivered; three business days after being deposited in the mail, postage prepaid, if mailed; when receipt is acknowledged by recipient's facsimile machine operator, if sent by facsimile transmission; and on the day delivered, if sent by overnight air courier guaranteeing next day delivery.

(c)No Inconsistent Agreements. The Company has not, as of the date hereof, entered into, nor shall it, on or after the date hereof, enter into, any agreement with respect to its securities that is inconsistent with the rights granted to the Holders herein or otherwise conflicts with the provisions hereof.

(d)Successors and Assigns. This Agreement shall be binding upon the Company and its successors and assigns.

(e)Counterparts. This Agreement may be executed in any number of counterparts and by the parties hereto in separate counterparts, each of which when so executed shall be deemed to be an original and all of which taken together shall constitute one and the same agreement.

(f)Headings. The headings in this Agreement are for convenience of reference only and shall not limit or otherwise affect the meaning hereof.

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(g)Governing Law. THIS AGREEMENT SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK WITHOUT REGARD TO PRINCIPLES OF CONFLICTS OF LAWS.

(h)Severability. If any one or more of the provisions contained herein, or the application thereof in any circumstance, is held invalid, illegal or unenforceable, the validity, legality and enforceability of any such provision in every other respect and of the remaining provisions contained herein shall not be affected or impaired thereby.

(i)Securities Held by the Company. Whenever the consent or approval of Holders of a specified percentage of principal amount of Securities is required hereunder, Securities held by the Company or its affiliates (other than subsequent Holders of Securities if such subsequent Holders are deemed to be affiliates solely by reason of their holdings of such Securities) shall not be counted in determining whether such consent or approval was given by the Holders of such required percentage.

(j)Submission to Jurisdiction; Waiver of Immunities. The Company hereby submits to the exclusive jurisdiction of the federal and state courts in the Borough of Manhattan in The City of New York in any suit or proceeding arising out of or relating to this Agreement or the transactions contemplated hereby.

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If the foregoing is in accordance with your understanding of our agreement, please sign and return to the Company a counterpart hereof, whereupon this instrument, along with all counterparts, will become a binding agreement among the several Initial Purchasers and the Company in accordance with its terms.

Very truly yours,

NORTHWESTERN CORPORATION

By: /s/ Paul J. Evans

Name: Paul J. Evans

Title: Treasurer

The foregoing Registration

Rights Agreement is hereby confirmed

and accepted as of the date first

above written.

CREDIT SUISSE SECURITIES (USA) LLC

DEUTSCHE BANK SECURITIES INC.

Acting on behalf of themselves

and as the Representatives of

the several Initial Purchasers

By: CREDIT SUISSE SECURITIES (USA) LLC

By: /s/ Jamie Welch

Name: Jamie Welch

Title: Managing Director

By: DEUTSCHE BANK SECURITIES INC.

By: /s/ Ben Smilchensky

Name: Ben Smilchensky

Title: Managing Director

By: /s/ Ryan Montgomery

Name: Ryan Montgomery

Title: Director

SCHEDULE A

Credit Suisse Securities (USA) LLC

Deutsche Bank Securities Inc.

Wachovia Capital Markets, LLC

KeyBanc Capital Markets, a Division of McDonald Investments Inc.

LaSalle Financial Services, Inc.

Piper Jaffray & Co.

Scotia Capital (USA) Inc.

Wedbush Morgan Securities Inc.

ANNEX A

Each broker-dealer that receives Exchange Securities for its own account pursuant to the Exchange Offer must acknowledge that it will deliver a prospectus in connection with any resale of such Exchange Securities. The Letter of Transmittal states that by so acknowledging and by delivering a prospectus, a broker-dealer will not be deemed to admit that it is an "underwriter" within the meaning of the Securities Act. This Prospectus, as it may be amended or supplemented from time to time, may be used by a broker-dealer in connection with resales of Exchange Securities received in exchange for Initial Securities where such Initial Securities were acquired by such broker-dealer as a result of market-making activities or other trading activities. The Company has agreed that, for a period of 180 days after the Expiration Date (as defined herein), it will make this Prospectus available to any broker-dealer for use in connection with any such resale. See "Plan of Distribution."

ANNEX B

Each broker-dealer that receives Exchange Securities for its own account in exchange for Securities, where such Initial Securities were acquired by such broker-dealer as a result of market-making activities or other trading activities, must acknowledge that it will deliver a prospectus in connection with any resale of such Exchange Securities. See "Plan of Distribution."

ANNEX C

PLAN OF DISTRIBUTION

Each broker-dealer that receives Exchange Securities for its own account pursuant to the Exchange Offer must acknowledge that it will deliver a prospectus in connection with any resale of such Exchange Securities. This Prospectus, as it may be amended or supplemented from time to time, may be used by a broker-dealer in connection with resales of Exchange Securities received in exchange for Initial Securities where such Initial Securities were acquired as a result of market-making activities or other trading activities. The Company has agreed that, for a period of 180 days after the Expiration Date, it will make this prospectus, as amended or supplemented, available to any broker-dealer for use in connection with any such resale. In addition, until , 20 , all dealers effecting transactions in the Exchange Securities may be required to deliver a prospectus.()

The Company will not receive any proceeds from any sale of Exchange Securities by broker-dealers. Exchange Securities received by broker-dealers for their own account pursuant to the Exchange Offer may be sold from time to time in one or more transactions in the over-the-counter market, in negotiated transactions, through the writing of options on the Exchange Securities or a combination of such methods of resale, at market prices prevailing at the time of resale, at prices related to such prevailing market prices or negotiated prices. Any such resale may be made directly to purchasers or to or through brokers or dealers who may receive compensation in the form of commissions or concessions from any such broker dealer or the purchasers of any such Exchange Securities. Any broker-dealer that resells Exchange Securities that were received by it for its own account pursuant to the Exchange Offer and any broker or dealer that participates in a distribution of such Exchange Securities may be deemed to be an "underwriter" within the meaning of the Securities Act and any profit on any such resale of Exchange Securities and any commission or concessions received by any such persons may be deemed to be underwriting compensation under the Securities Act. The Letter of Transmittal states that, by acknowledging that it will deliver and by delivering a prospectus, a broker-dealer will not be deemed to admit that it is an "underwriter" within the meaning of the Securities Act.

For a period of 180 days after the Expiration Date the Company will promptly send additional copies of this Prospectus and any amendment or supplement to this Prospectus to any broker-dealer that requests such documents in the Letter of Transmittal. The Company has agreed to pay all expenses incident to the Exchange Offer (including the expenses of one counsel for the Holders of the Securities) other than commissions or concessions of any brokers or dealers and will indemnify the Holders of the Securities (including any broker-dealers) against certain liabilities, including liabilities under the Securities Act.

_________________________

  In addition, the legend required by Item 502(b) of Regulation S-K will appear on the back cover page of the Exchange Offer prospectus.

ANNEX D

            CHECK HERE IF YOU ARE A BROKER-DEALER AND WISH TO RECEIVE 10 ADDITIONAL COPIES OF THE PROSPECTUS AND 10 COPIES OF ANY AMENDMENTS OR SUPPLEMENTS THERETO.

	Name: ____________________________________________
		Address: ___________________________________________
___________________________________________

If the undersigned is not a broker-dealer, the undersigned represents that it is not engaged in, and does not intend to engage in, a distribution of Exchange Securities. If the undersigned is a broker-dealer that will receive Exchange Securities for its own account in exchange for Initial Securities that were acquired as a result of market-making activities or other trading activities, it acknowledges that it will deliver a prospectus in connection with any resale of such Exchange Securities; however, by so acknowledging and by delivering a prospectus, the undersigned will not be deemed to admit that it is an "underwriter" within the meaning of the Securities Act.

EX-99

		NorthWestern Corporation d/b/a NorthWestern Energy 125 S. Dakota Avenue Sioux Falls, SD 57104-6403 www.northwesternenergy.com
News Release FOR IMMEDIATE RELEASE		NASDAQ-GS: NWEC
Media Contact: Claudia Rapkoch (866) 622-8081 claudia.rapkoch@northwestern.com	Investor Relations Contact: Dan Rausch (605) 978-2902 daniel.rausch@northwestern.com

NorthWestern Corporation Completes Sale of $150 Million First Mortgage Bonds

SIOUX FALLS, S.D. – Sept. 13, 2006 – Today, NorthWestern Corporation d/b/a NorthWestern Energy (NASDAQ-GS: NWEC) successfully closed on the sale of $150,000,000 aggregate principal amount of its 6.04% First Mortgage Bonds (the “Bonds”) due Sept. 1, 2016.

The proceeds from this offering, along with cash on hand, will be used by NorthWestern to repay the entire $150,000,000 in principal amount of its 7.30% First Mortgage Bonds due 2006, which become due on Dec. 1, 2006, and all related fees, expenses and premiums.

The Bonds will pay interest semiannually in arrears at a rate of 6.04% per year. Interest is payable on March 1 and September 1 of each year, beginning on March 1, 2007.

The Bonds have been rated by Fitch Ratings, Standard & Poor’s Rating Services, and Moody’s as BBB, BBB-, and Baa3, respectively. All three ratings are investment grade for the Bonds.

About NorthWestern Energy

NorthWestern Energy is one of the largest providers of electricity and natural gas in the Upper Midwest and Northwest, serving more than 628,500 customers in Montana, South Dakota and Nebraska. More information on NorthWestern Energy is available on the Company's Web site at www.northwesternenergy.com.

Special Note Regarding Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995.  Forward-looking statements often address our expected future business and financial performance, and often contain words such as “expects,” “anticipates,” “intends,” “plans,” “believes,” “seeks,” or “will.”  These statements are based upon our current expectations and speak only as of the date hereof.  Our actual future business and financial performance may differ materially and adversely from those expressed in any forward-looking statements as a result of various factors and uncertainties, including, but not limited to:

• the effect of the definitive agreement to sell NorthWestern to Babcock & Brown Infrastructure Limited (BBI), including the consummation of the transaction or the termination of the definitive agreement due to a number of factors, including the failure to obtain regulatory approvals or to satisfy other customary closing conditions;

– More –

NorthWestern Corporation Completes Sale of $150 Million First Mortgage Bonds

Sept. 13, 2006

Page 2

• our ability to avoid or mitigate adverse rulings or judgments against us in our pending litigation;

• unanticipated changes in availability of trade credit, usage, commodity prices, fuel supply costs or availability due to higher demand, shortages, weather conditions, transportation problems or other developments, may reduce revenues or may increase operating costs, each of which would adversely affect our liquidity;

• unscheduled generation outages or forced reductions in output, maintenance or repairs which may reduce revenues and increase cost of sales or may require additional capital expenditures or other increased operating costs;

• adverse changes in general economic and competitive conditions in our service territories; and

• potential additional adverse federal, state, or local legislation or regulation or adverse determinations by regulators could have a material adverse effect on our liquidity, results of operations and financial condition.

Our Annual Report on Form 10-K, recent and forthcoming Quarterly Reports on Form 10-Q, recent Current Reports on Form 8-K and other Securities and Exchange Commission filings discuss some of the important risk factors that may affect our business, results of operations and financial condition.  We undertake no obligation to revise or publicly update any forward-looking statements for any reason.

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