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SECURITIES AND EXCHANGE COMMISSION

Washington, D.C.  20549

FORM 10-K/A

Amendment No. 1

(Mark One)

[X]

ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE FISCAL YEAR ENDED DECEMBER 31, 2004 OR

[  ]

TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 FOR THE TRANSITION PERIOD FROM _____ TO _____.

Commission File No. 1-935

QUESTAR GAS COMPANY

(Exact name of registrant as specified in its charter)

State of Utah

 87-0155877

(State or other jurisdiction of

       (I.R.S. Employer

  incorporation or organization)

     Identification No.)

180 East 100 South, P.O. Box 45360, Salt Lake City, Utah

  84145-0360

(Address of principal executive offices)

     (Zip code)

Registrant's telephone number, including area code:

           (801) 324-5555

SECURITIES REGISTERED PURSUANT TO SECTION 12(b) OF THE ACT:

NONE

SECURITIES REGISTERED PURSUANT TO SECTION 12(g) OF THE ACT:

NONE

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.  Yes  X

No  ___ 

Indicate by check mark whether the registrant is an accelerated filer (as defined in Rule 12b-2 of the Exchange Act).  Yes            No   X    

Aggregate market value of the voting common equity held by non-affiliates of the registrant computed by reference to the price at which the common equity was last sold as of the last business day of the registrant’s most recently completed second quarter (June 30, 2004): $0.

On February 28, 2005, 9,189,626 shares of the registrant's Common Stock, $2.50 par value. (All shares are owned by Questar Corporation.)

Registrant meets the conditions set forth in General Instructions (I)(1)(a) and (b) of Form 10-K and is therefore filing this Form 10-K/A Report with the reduced disclosure format.

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EXPLANATORY NOTE

Questar Gas Company (Questar Gas or the Company) inadvertently omitted a Section 906 Certificate (Exhibit 32) and some required language in Part II Item 9A when it filed a Form 10-K for the year ended December 31, 2004, with the Securities and Exchange Commission on March 30, 2005. This amendment includes Items 9A and 15 as well as Exhibits 31.1, 31.2 and 32.  The Company is not making any changes to its financial statements.  This amendment is accurate as of the date of the Company’s originally filed Form 10-K and has not been updated to reflect any events that occurred subsequent to March 30, 2005.  The Company is including currently dated certifications as listed in revised Item 15.

TABLE OF CONTENTS

Heading

Page No.

PART II

Item 9A.

CONTROLS AND PROCEDURES

PART IV

Item 15.

EXHIBITS, FINANCIAL STATEMENT SCHEDULES

SIGNATURES

PART II

ITEM 9A.  CONTROLS AND PROCEDURES.

Evaluation of Disclosure Controls and Procedures.

The Company’s Chief Executive Officer and Chief Financial Officer have evaluated the effectiveness of the Company’s disclosure controls and procedures (as such term is defined in Rules 13a-15(e) under the Securities Exchange Act of 1934, as amended (the Exchange Act)) as of the end of the period covered by the report (the Evaluation Date). Based on such evaluation, such officers have concluded that, as of the Evaluation Date, the Company’s disclosure controls and procedures are effective in alerting them on a timely basis to material information relating to the Company required to be included in the Company’s reports filed or submitted under the Exchange Act. The Company’s Chief Executive Officer and Chief Financial Officer also concluded that the controls and procedures were effective in ensuring that information required to be disclosed by the Company in the reports that it files or submits under the Exchange Act is accumulated and communicated to the Company’s management including its principal executive and financial officers or persons performing similar functions as appropriate to allow timely decisions regarding required disclosure.

Changes in Internal Controls

Since the Evaluation Date, there have not been any changes in the Company’s internal controls or other factors during the most recent fiscal quarter that could materially affect such controls.

PART IV

ITEM 15.  EXHIBITS AND FINANCIAL STATEMENT SCHEDULES.

Financial statements and financial statement schedules filed as part of this report are listed in the index included in Item 8.

    (b)  Exhibits.  The following is a list of exhibits required to be filed as a part of this report in Item 15(b).

Exhibit No.

Description

 3.1.*

Restated Consolidated Articles of Incorporation dated August 15, 1980. (Exhibit No. 4(a) to Registration Statement No. 2-70087, filed December 1, 1980.)

 3.2.*

Certificate of Amendment to Restated Consolidated Articles of Incorporation dated May 13, 1982. (Exhibit No. 3(b) to Form 10-K Annual Report for 1982.)

 3.3.*

Certificate of Amendment to Restated Consolidated Articles of Incorporation dated May 10, 1983. (Included in Exhibit No. 4.1. to Registration Statement No. 2-84713, filed June 23, 1983.)

 3.4.*

Certificate of Amendment to Restated Consolidated Articles of Incorporation dated August 16, 1983. (Exhibit No. 3(a) to Form 8 Report amending the Company's Form 10-Q Report for Quarter Ended September 30, 1983.)

 3.5.*

Certificate of Amendment to Restated Consolidated Articles of Incorporation dated October 26, 1984. (Exhibit No. 3.5. to Form 10-K Annual Report for 1984.)

 3.6.*

Certificate of Amendment to Restated Consolidated Articles of Incorporation dated May 13, 1985. (Exhibit No. 3.1. to Form 10-Q Report for Quarter Ended June 30, 1985.)

 3.7.*

Articles of Amendment to Restated Consolidated Articles of Incorporation dated February 10, 1988. (Exhibit No. 3.7. to Form 10-K Annual Report for 1987.)

 3.8.*

Articles of Amendment to Restated Consolidated Articles of Incorporation dated December 31, 1997. (Exhibit No. 3.7. to Form 8-K Current Report for December 31, 1997.)

 3.9.*

Bylaws (as amended effective February 13, 2001). (Exhibit No. 3.9. to Form 10-K Annual Report for 2000.)

 4.*¹

Indenture dated as of May 1, 1992, between the Company and Citibank, as trustee, for the Company's Debt Securities. (Exhibit No. 4. to Form 10-Q Report for Quarter Ended June 30, 1992.)

10.1.*

Stipulations and Agreement, dated October 14, 1981, executed by the Company; Wexpro Company; the Utah Department of Business Regulations, Division of Public Utilities; the Utah Committee of Consumer Services; and the staff of the Public Service Commission of Wyoming. (Exhibit No. 10(a) to Form 10-K Annual Report for 1981.)

10.2.*

Gas Gathering Agreement between the Company and Questar Pipeline Company effective September 1, 1993. (This agreement has been transferred from Questar Pipeline to Questar Gas Management Company.) (Exhibit No. 10.11. to Form 10-K Annual Report for 1994.)

10.3.*

Amendment to Gas Gathering Agreement between the Company and Questar Gas Management Company effective September 1, 1997. (Exhibit No. 10.12. to Form 10-K Annual Report for 1997.)

24.*

Power of Attorney signed by the directors of Questar Gas Company on February 8, 2005. (Exhibit No. 24 to Form 10-K Annual Report for 2004.)

31.1.

Certification signed by A. K. Allred, the Company's Chief Executive Officer, pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.

31.2.

Certification signed by S. E. Parks, the Company's Chief Financial Officer, pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.

32.

Certification signed by Alan K. Allred and S. E. Parks, Questar Gas Company’s Chief Executive Officer and Chief Financial Officer, respectively, pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.

_______________________

*Exhibits so marked have been filed with the Securities and Exchange Commission as part of the referenced filing and are incorporated herein by reference.  

¹Wells Fargo Bank, N.A. serves as the successor trustee.

SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized, on the 22nd day of December, 2005.

QUESTAR GAS COMPANY

           (Registrant)

By /s/A. K. Allred

A. K. Allred

President and Chief Executive Officer

Pursuant to the requirements of the Securities Exchange Act of 1934, this report has been signed below by the following persons on behalf of the registrant and in the capacities and on the date indicated.

/s/A. K. Allred

Chief Executive Officer;

A. K. Allred

Director (Principal

Executive Officer)

/s/S. E. Parks

Vice President and Chief

S. E. Parks

Financial Officer (Principal

Financial Officer)

/s/D. M. Curtis                             

Vice President and Controller

D. M. Curtis

(Principal Accounting Officer)

*Keith O. Rattie

Chairman of the Board; Director

*A. K. Allred

Director

*Teresa Beck

Director

*W. W. Hawkins

Director

*Robert E. Kadlec

Director

*Dixie L. Leavitt

Director

*Gary G. Michael

Director

*Harris H. Simmons

Director

December 22, 2005

/s/ A. K. Allred

A. K. Allred, Attorney in Fact

Exhibits List

Exhibit No.

Description

 3.1.*

Restated Consolidated Articles of Incorporation dated August 15, 1980. (Exhibit No. 4(a) to Registration Statement No. 2-70087, filed December 1, 1980.)

 3.2.*

Certificate of Amendment to Restated Consolidated Articles of Incorporation dated May 13, 1982. (Exhibit No. 3(b) to Form 10-K Annual Report for 1982.)

 3.3.*

Certificate of Amendment to Restated Consolidated Articles of Incorporation dated May 10, 1983. (Included in Exhibit No. 4.1. to Registration Statement No. 2-84713, filed June 23, 1983.)

 3.4.*

Certificate of Amendment to Restated Consolidated Articles of Incorporation dated August 16, 1983. (Exhibit No. 3(a) to Form 8 Report amending the Company's Form 10-Q Report for Quarter Ended September 30, 1983.)

 3.5.*

Certificate of Amendment to Restated Consolidated Articles of Incorporation dated October 26, 1984. (Exhibit No. 3.5. to Form 10-K Annual Report for 1984.)

 3.6.*

Certificate of Amendment to Restated Consolidated Articles of Incorporation dated May 13, 1985. (Exhibit No. 3.1. to Form 10-Q Report for Quarter Ended June 30, 1985.)

 3.7.*

Articles of Amendment to Restated Consolidated Articles of Incorporation dated February 10, 1988. (Exhibit No. 3.7. to Form 10-K Annual Report for 1987.)

 3.8.*

Articles of Amendment to Restated Consolidated Articles of Incorporation dated December 31, 1997. (Exhibit No. 3.7. to Form 8-K Current Report for December 31, 1997.)

 3.9.*

Bylaws (as amended effective February 13, 2001). (Exhibit No. 3.9. to Form 10-K Annual Report for 2000.)

 4.*¹

Indenture dated as of May 1, 1992, between the Company and Citibank, as trustee, for the Company's Debt Securities. (Exhibit No. 4. to Form 10-Q Report for Quarter Ended June 30, 1992.)

10.1.*

Stipulations and Agreement, dated October 14, 1981, executed by the Company; Wexpro Company; the Utah Department of Business Regulations, Division of Public Utilities; the Utah Committee of Consumer Services; and the staff of the Public Service Commission of Wyoming. (Exhibit No. 10(a) to Form 10-K Annual Report for 1981.)

10.2.*

Gas Gathering Agreement between the Company and Questar Pipeline Company effective September 1, 1993. (This agreement has been transferred from Questar Pipeline to Questar Gas Management Company.) (Exhibit No. 10.11. to Form 10-K Annual Report for 1994.)

10.3.*

Amendment to Gas Gathering Agreement between the Company and Questar Gas Management Company effective September 1, 1997. (Exhibit No. 10.12. to Form 10-K Annual Report for 1997.)

24.*

Power of Attorney by the directors of Questar Gas Company on February 8, 2005. (Exhibit No. 24 to Form 10-K Annual Report for 2004.)

31.1.

Certification signed by A. K. Allred, the Company's Chief Executive Officer, pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.

31.2.

Certification signed by S. E. Parks, the Company's Chief Financial Officer, pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.

32.

Certification signed by Alan K. Allred and S. E. Parks, Questar Gas Company’s Chief Executive Officer and Chief Financial Officer, respectively, pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.

_______________________

*Exhibits so marked have been filed with the Securities and Exchange Commission as part of the referenced filing and are incorporated herein by reference.  

¹Wells Fargo Bank, N.A. serves as the successor trustee.

Exhibit No. 31.1.

CERTIFICATION

I, A. K. Allred, certify that:

1.

I have reviewed this annual report on Form 10-K for 2004 as amended of Questar Gas Company;

2.

Based on my knowledge, this annual report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this annual report;

3.

Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4.

The registrant's other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and we have:

a)

designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b)

designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c)

evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d)

disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the registrant's most recent fiscal quarter (the registrant's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting.

5.

The registrant's other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant's auditors and the audit committee of registrant's board of directors (or persons performing the equivalent function):

a)

all significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant's ability to record, process, summarize and report financial information; and

b)

any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting.

December 22, 2005

By  /s/A. K. Allred

      A. K. Allred

      President and Chief Executive Officer

Exhibit No. 31.2.

CERTIFICATION

I. S. E. Parks, certify that:

1.

I have reviewed this annual report on Form 10-K for 2004 as amended of Questar Gas Company;

2.

Based on my knowledge, this annual report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this annual report;

3.

Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4.

The registrant's other certifying officer and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)) for the registrant and we have:

a)

designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b)

designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c)

evaluated the effectiveness of the registrant's disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d)

disclosed in this report any change in the registrant's internal control over financial reporting that occurred during the registrant's most recent fiscal quarter (the registrant's fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant's internal control over financial reporting.

5.

The registrant's other certifying officer and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant's auditors and the audit committee of registrant's board of directors (or persons performing the equivalent function):

a)

all significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant's ability to record, process, summarize and report financial information; and

b)

any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant's internal control over financial reporting.

December 22, 2005

By  /s/S. E. Parks

     S. E. Parks

     Vice President and Chief Financial Officer

Exhibit No. 32.

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Annual Report of Questar Gas Company (the Company) on Form 10-K as amended for the period ending December 31, 2004, as filed with the Securities and Exchange Commission on the date hereof (the Report), Alan K. Allred, Chief Executive Officer of the Company, and S. E. Parks, Vice President and Chief Financial Officer of the Company, each hereby certifies, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that, to the best of his knowledge:

(1)

The Report fully complies with the requirements of Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934; and

(2)

The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

QUESTAR GAS COMPANY

December 22, 2005

/s/A. K. Allred__   ___________________

A. K. Allred

President and Chief Executive Officer

December 22, 2005

/s/S. E. Parks________________________

S. E. Parks

Vice President and Chief Financial Officer