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): December 7, 2010

FIRST INTERSTATE BANCSYSTEM, INC.

(Exact name of registrant as specified in its charter)

Montana	001-34653	81-0331430
(State or other jurisdiction of	(Commission	(IRS Employer
incorporation or organization)	File No.)	Identification No.)

401 North 31^st Street, Billings, MT
(Address of principal executive offices)

(406) 255-5390
(Registrant’s telephone number, including area code)

Not Applicable
(Former name or former address, if changed since last report)

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:

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 8.01 Other Events.

     On December 7, 2010, First Interstate BancSystem, Inc. (the “Registrant”) issued a press release announcing the declaration of a quarterly dividend to common shareholders of $0.1125 per share to be paid on January 17, 2011 to shareholders of record as of January 3, 2011.

Item 9.01 Financial Statements and Exhibits.

     (d) Exhibit 99.1 — Press Release dated December 7, 2010 announcing declaration of quarterly dividend to common shareholders.

SIGNATURE

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

Dated: December 7, 2010

FIRST INTERSTATE BANCSYSTEM, INC.
By:	/s/ LYLE R. KNIGHT
	Lyle R. Knight
	President and Chief Executive Officer

EX-99.1

Exhibit 99.1

First Interstate BancSystem, Inc. Announces Quarterly Dividend

Company Release: December 7, 2010

First Interstate BancSystem, Inc.’s (Nasdaq: FIBK) Executive Committee of the Board of Directors, at a meeting held on December 6, 2010, declared a quarterly dividend of $.1125 per common share. The dividend is payable on January 17, 2011 to owners of record on January 3, 2011.

First Interstate BancSystem, Inc. is a financial services holding company, headquartered in Billings, Montana, with $7.3 billion in assets as of September 30, 2010. It is the parent company of First Interstate Bank, a community bank operating 72 offices throughout Montana, Wyoming and western South Dakota. As a recognized leader in community banking services with 22 consecutive years of profitability, First Interstate remains a family business whose culture is driven by strong family and corporate values, as well as a commitment to long-term organic growth, exemplary customer service, exceeding customer expectations through its products and services and supporting with leadership and resources, the communities it serves.

Contact:
Marcy Mutch
Investor Relations
First Interstate BancSystem, Inc.
401 North 31st Street
Billings, Montana 59116
+1 406-255-5322
investor.relations@fib.com