150,000,000 QUESTAR GAS COMPANY (a Utah corporation) $50,000,000 6.30% Notes due 2018 $100,000,000 7.20% Notes due 2038 PURCHASE AGREEMENT

Exhibit 1.1

$150,000,000
QUESTAR GAS COMPANY

(a Utah corporation)

$50,000,000 6.30% Notes due 2018

$100,000,000 7.20% Notes due 2038

PURCHASE AGREEMENT

Dated: March 24, 2008

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TABLE OF CONTENTS

Page

SECTION 1. Representations and Warranties of the Company.

SECTION 2. Sale and Delivery to Underwriters; Closing.

SECTION 3. Covenants of the Company

SECTION 4. Payment of Expenses.

SECTION 5. Conditions of Underwriters’ Obligations

SECTION 6. Indemnification.

SECTION 7. Contribution.

SECTION 8. Representations, Warranties and Agreements to Survive Delivery.

SECTION 9. Termination of Agreement.

SECTION 10. Default by One or More of the Underwriters

SECTION 11. Notices.

SECTION 12. Parties.

SECTION 13. No Advisory or Fiduciary Responsibility.

SECTION 14. GOVERNING LAW AND TIME

SECTION 15. Effect of Headings.

SCHEDULES

Schedule A

List of Underwriters

Sch. A-1

Schedule B

Final Term Sheet

Sch. B-1

Schedule C

Issuer Free Writing Prospectuses

Sch. C-1

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$150,000,000
QUESTAR GAS COMPANY

(a Utah corporation)

$50,000,000 6.30% Notes due 2018

$100,000,000 7.20% Notes due 2038

PURCHASE AGREEMENT

March 24, 2008

Barclays Capital Inc.
▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇
▇▇▇ ▇▇▇▇, ▇▇ ▇▇▇▇▇

▇.▇. ▇▇▇▇▇▇ Securities Inc.
▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇
▇▇▇ ▇▇▇▇, ▇▇ ▇▇▇▇▇

as Representatives of the several Underwriters

Ladies and Gentlemen:

Questar Gas Company, a Utah corporation (the “Company”), confirms its agreement with Barclays Capital Inc. and ▇.▇. ▇▇▇▇▇▇ Securities Inc. Inc. and each of the other Underwriters named in Schedule A hereto (collectively, the “Underwriters,” which term shall also include any underwriter substituted as hereinafter provided in Section 10 hereof), for whom Barclays Capital Inc. and ▇.▇. ▇▇▇▇▇▇ Securities Inc. are acting as representatives (in such capacity, the “Representatives”), with respect to the issue and sale by the Company and the purchase by the Underwriters, acting severally and not jointly, of the respective principal amounts set forth in Schedule A of $50,000,000 aggregate principal amount of the Company’s 6.30% Notes due 2018 (the “Notes due 2018”) and $100,000,000 aggregate principal amount of the Company’s 7.20% Notes due 2038) (the “Notes due 2038”) (collectively, the “Securities”). The Securities are to be issued pursuant to an indenture dated as of May 1, 1992 (the “Indenture”) between the Company and ▇▇▇▇▇ Fargo Bank, NA, as trustee (the “Trustee”). The term “Indenture,” as used herein, includes the Officers’ Certificates (as defined in the Indenture) establishing the form and terms of the Securities pursuant to Sections 201 and 301 of the Indenture.

The Company understands that the Underwriters propose to make a public offering of the Securities as soon as the Representatives deem advisable after this Agreement has been executed and delivered and the Indenture has been qualified under the Trust Indenture Act of 1939, as amended, and the rules and regulations promulgated thereunder (collectively, the “Trust Indenture Act”).

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SECTION 1. Representations and Warranties of the Company. The Company represents and warrants to each Underwriter as of the date hereof, as of the Closing Time referred to in Section 2(b) hereof, and agrees with each Underwriter, as follows:

(a)

The Company has prepared and filed with the Securities and Exchange Commission (the “Commission”) a registration statement on Form S-3 (File No. 333-147317), which contains a base prospectus (the “Base Prospectus”), to be used in connection with the public offering and sale of the Securities. Such registration statement, as amended, including the financial statements, exhibits and schedules thereto, at each time of effectiveness under the Securities Act of 1933, as amended, and the rules and regulations promulgated thereunder (collectively, the “Securities Act”), including any required information deemed to be a part thereof at the time of effectiveness pursuant to Rule 430B under the Securities Act or the Securities Exchange Act of 1934, as amended, and the rules and regulations promulgated thereunder (collectively, the “Exchange Act”), is called the “Registration Statement.” Any registration statement filed by the Company pursuant to Rule 462(b) under the Securities Act is called the “Rule 462(b) Registration Statement,” and from and after the date and time of filing of the Rule 462(b) Registration Statement the term “Registration Statement” shall include the Rule 462(b) Registration Statement. Any preliminary prospectus supplement to the Base Prospectus that describes the Securities and the offering thereof and is used prior to filing of the Prospectus is called, together with the Base Prospectus, a “preliminary prospectus.” The term “Prospectus” shall mean the final prospectus supplement relating to the Securities, together with the Base Prospectus, that is first filed pursuant to Rule 424(b) after the date and time that this Agreement is executed and delivered by the parties hereto. Any reference herein to the Registration Statement, any preliminary prospectus or the Prospectus shall be deemed to refer to and include the documents incorporated by reference therein pursuant to Item 12 of Form S-3 under the Securities Act; any reference to any amendment or supplement to any preliminary prospectus or the Prospectus shall be deemed to refer to and include any documents filed after the date of such preliminary prospectus or Prospectus, as the case may be, under the Exchange Act, and incorporated by reference in such preliminary prospectus or Prospectus, as the case may be; and any reference to any amendment to the Registration Statement shall be deemed to refer to and include any annual report of the Company filed pursuant to Section 13(a) or 15(d) of the Exchange Act after the effective date of the Registration Statement that is incorporated by reference in the Registration Statement. All references in this Agreement to the Registration Statement, the Rule 462(b) Registration Statement, a preliminary prospectus, the Prospectus, or any amendments or supplements to any of the foregoing, shall include any copy thereof filed with the Commission pursuant to its Electronic Data Gathering, Analysis and Retrieval System (“▇▇▇▇▇”).

(b)

Compliance with Registration Requirements. The Company meets the requirements for use of Form S-3 under the Securities Act. Each of the Registration Statement and any Rule 462(b) Registration Statement has become effective under the Securities Act and no stop order suspending the effectiveness of the Registration Statement or any Rule 462(b) Registration Statement has been issued under the Securities Act and no proceedings for that purpose have been instituted or are pending or, to the knowledge of the Company, are contemplated by the Commission, and any request on the part of the Commission for additional information has been complied with.

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At the respective times the Registration Statement, any Rule 462(b) Registration Statement and any post-effective amendments thereto became effective and at the date hereof, the Registration Statement, the Rule 462(b) Registration Statement and any amendments and supplements thereto complied and will comply in all material respects with the requirements of the Securities Act and the Trust Indenture Act, and did not and will not 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. Neither the Prospectus nor any amendments or supplements thereto, at the time the Prospectus or any such amendment or supplement was issued and at the Closing Time, included or will include an untrue statement of a material fact or omitted or will omit to state a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading. The representations and warranties in this subsection shall not apply to statements in or omissions from the Registration Statement or any post-effective amendment thereto or Prospectus or any amendment or supplement thereto made in reliance upon and in conformity with information furnished to the Company in writing by or on behalf of any Underwriter through the Representatives expressly for use in the Registration Statement or Prospectus, it being understood and agreed that the only such information furnished by the Representatives consists of the information described as such in Section 6 hereof.

Each preliminary prospectus and the prospectus filed as part of the Registration Statement as originally filed or as part of any amendment thereto, or filed pursuant to Rule 424 under the Securities Act, complied when so filed in all material respects with the Securities Act Regulations and each preliminary prospectus and the Prospectus delivered to the Underwriters for use in connection with this offering was identical to the electronically transmitted copies thereof filed with the Commission pursuant to ▇▇▇▇▇, except to the extent permitted by Regulation S-T.

(c)

Incorporated Documents. The documents incorporated or deemed to be incorporated by reference in the Registration Statement, the Disclosure Package (as defined below) and the Prospectus, at the times they were or hereafter are filed with the Commission, complied and will comply in all material respects with the requirements of the Exchange Act, and, when read together with the other information in the Disclosure Package and the Prospectus, at the times the Registration Statement became effective, at the time the Prospectus was issued and at the Closing Time, did not and will not 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, in light of the circumstances under which they were made, not misleading.

(d)

Disclosure Package. The term “Disclosure Package” shall mean (i) the Base Prospectus, including any preliminary prospectus supplement, as amended or supplemented, (ii) the issuer free writing prospectuses as defined in Rule 433 of the Securities Act (each, an “Issuer Free Writing Prospectus”), if any, identified in Schedule C hereto, (iii) any other free writing prospectus that the parties hereto shall hereafter expressly agree in writing to treat as part of the Disclosure Package and (iv) the Final Term Sheet (as defined herein), which also shall be identified in Schedule C hereto. As of 6:38 p.m. (Eastern time) on the date of this Agreement (the “Applicable Time”), the Disclosure Package did not contain any untrue statement of a material fact or 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

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sentence does not apply to statements in or omissions from the Disclosure Package based upon and in conformity with written information furnished to the Company by or on behalf of any Underwriter through the Representatives specifically for use therein, it being understood and agreed that the only such information furnished by the Representatives consists of the information described as such in Section 6 hereof.

(e)

Company Not Ineligible Issuer. (i) At the earliest time after the filing of the Registration Statement relating to the Securities that the Company or another offering participant made a bona fide offer (within the meaning of Rule 164(h)(2)) of the Securities Act and (ii) as of the date of the execution and delivery of this Agreement (with such date being used as the determination date for purposes of this clause (ii)), the Company was not and is not an Ineligible Issuer (as defined in Rule 405 of the Securities Act) without taking account of any determination by the Commission pursuant to Rule 405 of the Securities Act that it is not necessary that the Company be considered an Ineligible Issuer.

(f)

Issuer Free Writing Prospectuses. Each Issuer Free Writing Prospectus, as of its issue date and at all subsequent times through the completion of the offering or until any earlier date that the Company notified or notifies the Representatives as described in the next sentence, did not, does not and will not include any information that conflicted, conflicts or will conflict with the information contained in the Registration Statement, any preliminary prospectus or the Prospectus, including in each case, any document incorporated by reference therein that has not been superseded or modified. If at any time following issuance of an Issuer Free Writing Prospectus there occurred or occurs an event or development as a result of which such Issuer Free Writing Prospectus conflicted or would conflict with the information contained in the Registration Statement, any preliminary prospectus or the Prospectus, the Company has promptly notified or will promptly notify the Representatives and has promptly amended or supplemented or will promptly amend or supplement, at its own expense, such Issuer Free Writing Prospectus to eliminate or correct such conflict. The foregoing two sentences do not apply to statements in or omissions from any Issuer Free Writing Prospectus based upon and in conformity with written information furnished to the Company by or on behalf of any Underwriter through the Representatives specifically for use therein, it being understood and agreed that the only such information furnished by the Representatives consists of the information described as such in Section 6 hereof.

(g)

Distribution of Offering Material By the Company. The Company has not distributed and will not distribute, prior to the later of the Closing Time and the completion of the Underwriters’ distribution of the Securities, any offering material in connection with the offering and sale of the Securities other than a preliminary prospectus, the Prospectus, any Issuer Free Writing Prospectus reviewed and consented to by the Representatives and included in Schedule C hereto or the Registration Statement.

(h)

Accountants. The accountants who certified the financial statements and supporting schedules included or incorporated by reference in the Disclosure Package and the Prospectus are, to the best knowledge of the Company, a registered public accounting firm independent of the Company as required by the Securities Act and the rules and regulations of the Public Company Accounting Oversight Board.

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(i)

Financial Statements. The financial statements included in the Registration Statement, the Disclosure Package and the Prospectus present fairly the financial position of the Company and its consolidated subsidiaries as at the dates indicated and the results of their operations for the periods specified; except as otherwise stated in such document, such financial statements have been prepared in conformity with generally accepted accounting principles applied on a consistent basis; and the supporting schedules included in the Registration Statement present fairly the information required to be stated therein. The selected financial data included in each of the preliminary prospectus and Prospectus present fairly the information shown therein and have been compiled on a basis consistent with that of the audited financial statements included in such document. The Company’s ratio of earnings to fixed charges set forth in each of the preliminary prospectus and the Prospectus have been calculated in compliance with Item 503(d) of Regulation S-K under the Securities Act.

(j)

Material Changes or Material Transactions. Since the respective dates as of which information is given in the Registration Statement, the Disclosure Package and the Prospectus, except as otherwise stated therein, (a) there has been no material adverse change in the condition, financial or otherwise, or in the earnings, business affairs or business prospects of the Company and its subsidiaries considered as one enterprise, whether or not arising in the ordinary course of business, (b) there have been no transactions entered into by the Company or any of its subsidiaries, other than those in the ordinary course of business, which are material with respect to the Company and its subsidiaries considered as one enterprise, and (c) except for the regular dividends, there has been no dividend or distribution of any kind declared, paid or made by the Company on any class of its capital stock.

(k)

Due Incorporation and Qualification. The Company has been duly incorporated and is validly existing as a corporation in good standing under the laws of the State of Utah with corporate power and authority to own, lease and operate its properties and to conduct its business as described in the Disclosure Package and the Prospectus; and the Company is duly qualified as a foreign corporation to transact business and is in good standing in each jurisdiction in which such qualification is required, whether by reason of the ownership or leasing of property or the conduct of business, except where the failure to so qualify or be in good standing would not have a material adverse effect on the condition, financial or otherwise, or the earnings, business affairs or business prospects of the Company and its subsidiaries considered as one enterprise (a “Material Adverse Effect”).

(l)

Subsidiaries. Each subsidiary of the Company has been duly incorporated and is validly existing as a corporation in good standing under the laws of the jurisdiction of its incorporation, has corporate power and authority to own, lease and operate its properties and to conduct its business as described in the Disclosure Package and the Prospectus and is duly qualified as a foreign corporation to transact business and is in good standing in each jurisdiction in which such qualification is required, whether by reason of the ownership of property or the conduct of business, except where the failure to so qualify or be in good standing would not have a Material Adverse Effect; and all of the issued and outstanding capital stock of each subsidiary has been duly authorized and validly issued, is fully paid and nonassessable and is owned by the Company, directly or through subsidiaries, free and clear of any security interest, mortgage, pledge, lien, encumbrance, claim or equity.

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(m)

Capital Stock. The shares of issued and outstanding common stock of the Company have been duly authorized and validly issued and are fully paid and nonassessable.

(n)

Authorization of Agreement. This Agreement has been duly authorized, executed and delivered by the Company.

(o)

Authorization and Validity of the Indenture and the Securities. The Securities have been duly authorized and, at the Closing Time, will have been duly executed by the Company and, when authenticated, issued and delivered in the manner provided for in the Indenture and delivered against payment of the purchase price therefor as provided in this Agreement, will constitute valid and legally binding obligations of the Company, enforceable against the Company in accordance with their terms, subject to bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium and similar laws of general applicability relating to or affecting creditors’ rights and general equitable principles, and will be entitled to the benefits provided by the Indenture, which will be substantially in the form filed as an exhibit to the Registration Statement; the Indenture has been duly authorized, executed and delivered by the Company and the Indenture has been duly qualified under the Trust Indenture Act and constitutes a valid and legally binding instrument of the Company, enforceable against the Company in accordance with its terms, subject to bankruptcy, insolvency, fraudulent transfer, reorganization, moratorium and similar laws of general applicability relating to or affecting creditors’ rights and general equitable principles; and the Securities and the Indenture conform to the respective descriptions thereof in the Disclosure Package and the Prospectus.

(p)

No Defaults; Regulatory Approvals. Neither the Company nor any of its subsidiaries is in violation of its charter or bylaws or in default in the performance or observance of any obligation, agreement, covenant or condition contained in any contract, indenture, mortgage, loan agreement, note, lease or other instrument to which the Company or any of its subsidiaries is a party or by which it or any of them may be bound, or to which any of the property or assets of the Company or any of its subsidiaries is subject, which violations or defaults in the aggregate would have a Material Adverse Effect; and the execution and delivery of this Agreement and the consummation of the transactions contemplated herein, in the Disclosure Package and in the Prospectus have been duly authorized by all necessary corporate action and will not conflict with or constitute a breach of, or a default under, or result in the creation or imposition of any lien, charge or encumbrance upon any property or assets of the Company or any of its subsidiaries, except as expressly contemplated in the Indenture or except as would not have a Material Adverse Effect, pursuant to any contract, indenture, mortgage, loan agreement, note, lease or other instrument to which the Company or any of its subsidiaries is a party or by which it or any of them may be bound, or to which any of the property or assets of the Company or any of its subsidiaries is subject, nor will such action result in any violation of the provisions of the charter or bylaws of the Company or, except as would not have a Material Adverse Effect, any applicable law, administrative regulation or administrative or court decree.

(q)

Legal Proceedings; Contracts. There is no action, suit or proceeding before or brought by any court or governmental agency or body, domestic or foreign, now pending, or, to the knowledge of the Company, threatened, against the Company or any of its subsidiaries, which is required to be disclosed in the Registration Statement, the Disclosure Package or the Prospectus (other than as disclosed therein) or which would reasonably be expected to result in a

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Material Adverse Effect, or which would materially and adversely affect the properties or assets thereof or the consummation of the transactions contemplated by this Agreement or the performance by the Company of its obligation hereunder; all pending legal or governmental proceedings to which the Company or any of its subsidiaries is a party or which any of their respective property is subject which are not described in the Registration Statement, the Disclosure Package and the Prospectus, including ordinary routine litigation incidental to the business, considered in the aggregate, would not reasonably be expected to cause a Material Adverse Effect; and there are no contracts or documents of the Company or any of its subsidiaries which are required to be filed as exhibits to the Registration Statement by the Securities Act which have not been so filed.

(r)

No Governmental Authorization. No authorization, approval or consent of any court or governmental authority or agency is necessary in connection with the sale of the Securities hereunder, except such as may be required under the Securities Act and state securities laws and except as have been obtained.

(s)

Possession of Permits. The Company and its subsidiaries possess such valid franchises, certificates of convenience and necessity, easements, rights-of-way, operating rights, licenses, permits, consents, authorizations and orders of governmental political subdivisions or regulatory authorities as are necessary to conduct the business now operated by them, except those the failure of which to possess would not have a Material Adverse Effect, and neither the Company nor any of its subsidiaries has received any notice of proceedings relating to the revocation or modification thereof which, singly or in the aggregate, if the subject of an unfavorable decision, ruling or finding would have a Material Adverse Effect.

(t)

Investment Company Act. Neither the Company nor any of its subsidiaries is regulated or required to be registered as an “investment company” under the Investment Company Act of 1940, as amended (the “Investment Company Act”).

(u)

Ratings. The Securities are rated A3 by ▇▇▇▇▇’▇ Investors Service, Inc. and A- by Standard & Poor’s Ratings Services, or such other rating as to which the Company shall have most recently notified the Underwriters pursuant to Section 5(i) hereof.

(v)

Internal Controls and Procedures. The Company maintains on a consolidated basis (i) effective internal control over financial reporting as defined in Rule 13a-15(f) and Rule 15d-15(f) under the Exchange Act, and (ii) a system of internal accounting controls sufficient to provide reasonable assurance that (A) transactions are executed in accordance with management’s general or specific authorizations; (B) transactions are recorded as necessary to permit preparation of financial statements in conformity with generally accepted accounting principles and to maintain asset accountability; (C) access to assets is permitted only in accordance with management’s general or specific authorization; and (D) the recorded accountability for assets is compared with the existing assets at reasonable intervals and appropriate action is taken with respect to any differences.

(w)

No Material Weakness in Internal Controls. Except as disclosed in the Disclosure Package and the Prospectus, or in any document incorporated by reference therein, since the end of the Company’s most recent audited fiscal year, there has been (i) no material weakness in the

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Company’s internal control over financial reporting (whether or not remediated) and (ii) no change in the Company’s internal control over financial reporting that has materially affected, or is reasonably likely to materially affect, the Company’s internal control over financial reporting.

(x)

▇▇▇▇▇▇▇▇-▇▇▇▇▇ Compliance. There is and has been no failure on the part of the Company and any of the Company’s directors or officers, in their capacities as such, to comply with any provision of the ▇▇▇▇▇▇▇▇-▇▇▇▇▇ Act of 2002 and the rules and regulations promulgated in connection therewith (the “▇▇▇▇▇▇▇▇-▇▇▇▇▇ Act”), including Section 402 related to loans and Sections 302 and 906 related to certifications.

(y)

Additional Certifications. Any certificate signed by any director or officer of the Company and delivered to the Representatives or to counsel for the Underwriters shall be deemed a representation and warranty by the Company to the Underwriters as to the matters covered thereby.

SECTION 2. Sale and Delivery to Underwriters; Closing.

(a)

Securities. On the basis of the representations and warranties herein contained and subject to the terms and conditions herein set forth, the Company agrees to sell to each Underwriter, severally and not jointly, and each Underwriter, severally and not jointly, agrees to purchase from the Company, at a price of 99.290% of the principal amount of the Notes due 2018 and 99.062% of the principal amount of the Notes due 2038, plus accrued interest, if any, from the Closing Time, the respective aggregate principal amounts of Securities set forth in Schedule A opposite the name of such Underwriter, plus any additional principal amounts of Securities which such Underwriter may become obligated to purchase pursuant to the provisions of Section 10 hereof.

(b)

Payment. Payment of the purchase price for, and delivery of certificates for, the Securities shall be made at the offices of Skadden, Arps, Slate, ▇▇▇▇▇▇▇ & ▇▇▇▇ LLP, Four Times Square, New York, NY 10036, or at such other place as shall be agreed upon by the Representatives and the Company, at 10:00 A.M. (New York City time) on the third business day after the date hereof (unless postponed in accordance with the provisions of Section 10), or such other time not later than ten business days after such date as shall be agreed upon by the Representatives and the Company (such time and date of payment and delivery being herein called “Closing Time”).

Payment shall be made to the Company by wire transfer of immediately available funds to a bank account designated by the Company, against delivery to the Representatives for the respective accounts of the Underwriters of certificates for the Securities to be purchased by them. It is understood that each Underwriter has authorized the Representatives, for its account, to accept delivery of, receipt for, and make payment of the purchase price for, the Securities which it has agreed to purchase. ▇.▇. ▇▇▇▇▇▇ Securities Inc., individually and not as a representative of the Underwriters, may (but shall not be obligated to) make payment of the purchase price for the Securities to be purchased by any Underwriter whose funds have not been received by Closing Time, but such payment shall not relieve such Underwriter from its obligations hereunder.

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(c)

Denominations; Registration. Certificates for the Securities shall be in minimum denominations of $2,000 and integral multiples of $1,000 and registered in such names as the Representatives may request in writing at least one full business day before Closing Time. The Securities will be made available for examination and packaging by the Representatives in The City of New York not later than 10:00 A.M. (New York City time) on the business day prior to Closing Time.

SECTION 3. Covenants of the Company. The Company covenants with each Underwriter as follows:

(a)

Compliance with Securities Regulations and Commission Requests. The Company, subject to Section 3(b) hereof, will comply with the requirements of Rule 430B, and will notify the Representatives immediately, and confirm the notice in writing, (i) when any post-effective amendment to the Registration Statement shall become effective, or any supplement to the Prospectus or any amended Prospectus or any Issuer Free Writing Prospectus shall have been filed, (ii) of the receipt of any comments from the Commission concerning the Registration Statement, (iii) of any request by the Commission for any amendment to the Registration Statement or any amendment or supplement to the Prospectus or for additional information, and (iv) of the issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement or of any order preventing or suspending the use of any preliminary prospectus, or of the suspension of the qualification of the Securities for offering or sale in any jurisdiction, or of the initiation or threatening of any proceedings for any of such purposes. The Company will promptly effect the filings necessary pursuant to Rule 424(b) and will take such steps as it deems necessary to ascertain promptly whether the form of prospectus transmitted for filing under Rule 424(b) was received for filing by the Commission and, in the event that it was not, it will promptly file such prospectus. The Company will make every reasonable effort to prevent the issuance of any stop order and, if any stop order is issued, to obtain the lifting thereof at the earliest possible moment.

(b)

Representatives’ Review of Proposed Amendments and Supplements. During the period beginning on the Applicable Time and ending on the later of the Closing Time or such date, as in the opinion of counsel for the Underwriters, the Prospectus is no longer required by law to be delivered in connection with sales by an Underwriter or dealer, including in circumstances where such requirement may be satisfied pursuant to Rule 172 (the “Prospectus Delivery Period”), prior to amending or supplementing the Registration Statement, the Disclosure Package or the Prospectus (including any amendment or supplement through incorporation by reference of any report filed under the Exchange Act), the Company shall furnish to the Representatives for review a copy of each such proposed amendment or supplement, and the Company shall not file or use any such proposed amendment or supplement to which the Representatives reasonably object.

(c)

Amendments and Supplements to the Registration Statement, Prospectus and Other Securities Act Matters. The Company will comply with the Securities Act, the Exchange Act and the Trust Indenture Act so as to permit the completion of the distribution of the Securities as contemplated in this Agreement and in the Disclosure

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Package and the Prospectus. If, during the Prospectus Delivery Period, any event or development shall occur or condition exist as a result of which the Disclosure Package or the Prospectus as then amended or supplemented would include any untrue statement of a material fact or 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 or then prevailing, as the case may be, not misleading, or if it shall be necessary to amend or supplement the Disclosure Package or the Prospectus, or to file under the Exchange Act any document incorporated by reference in the Disclosure Package or the Prospectus, in order to make the statements therein, in the light of the circumstances under which they were made or then prevailing, as the case may be, not misleading, or if in the opinion of the Representatives it is otherwise necessary to amend or supplement the Registration Statement, the Disclosure Package or the Prospectus, or to file under the Exchange Act any document incorporated by reference in the Disclosure Package or the Prospectus, or to file a new registration statement containing the Prospectus, in order to comply with law, including in connection with the delivery of the Prospectus, the Company agrees to (i) notify the Representatives of any such event or condition and (ii) promptly prepare (subject to Section 3(b) and 3(e) hereof), file with the Commission (and use its best efforts to have any amendment to the Registration Statement or any new registration statement to be declared effective) and furnish at its own expense to the Underwriters and to dealers, amendments or supplements to the Registration Statement, the Disclosure Package or the Prospectus, or any new registration statement, necessary in order to make the statements in the Disclosure Package or the Prospectus as so amended or supplemented, in the light of the circumstances then prevailing or under which they were made, as the case may be, not misleading or so that the Registration Statement, the Disclosure Package or the Prospectus, as amended or supplemented, will comply with law.

(d)

Final Term Sheet. The Company will prepare final term sheets containing only a description of the Securities, in a form approved by the Representatives and contained in Schedule B hereto, and will file such term sheets pursuant to Rule 433(d) under the Securities Act within the time required by such rule (such term sheets, collectively, the “Final Term Sheet”).

(e)

Permitted Free Writing Prospectuses. The Company represents that it has not made, and agrees that, unless it obtains the prior written consent of the Representatives (which shall not be unreasonably withheld), it will not make, any offer relating to the Securities that would constitute an Issuer Free Writing Prospectus or that would otherwise constitute a “free writing prospectus” (as defined in Rule 405 of the Securities Act) required to be filed by the Company with the Commission or retained by the Company under Rule 433 of the Securities Act; provided that the prior written consent of the Representatives hereto shall be deemed to have been given in respect of the Free Writing Prospectuses included in Schedule C hereto. Any such free writing prospectus consented to by the Representatives is hereinafter referred to as a “Permitted Free Writing Prospectus.” The Company agrees that (i) it has treated and will treat, as the case may be, each Permitted Free Writing Prospectus as an Issuer Free Writing Prospectus, and (ii) has complied and will comply, as the case may be, with the requirements of Rules 164 and 433 of the Securities Act applicable to any Permitted Free

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Writing Prospectus, including in respect of timely filing with the Commission, legending and record keeping. Each Underwriter represents that it has not and will not use any written communication that constitutes an offer to sell or the solicitation of an offer to buy the Securities other than a free writing prospectus that (a) is not an “issuer free writing prospectus” as defined in Rule 433, and (b) contains only (i) information describing the preliminary terms of the Securities or their offering, (ii) information permitted by Rule 134 under the Securities Act or (iii) information that describes the final terms of the Securities or their offering and that is included in the Final Term Sheet of the Company contemplated in Section 3(d) hereof.

(f)

Delivery of Registration Statements. The Company has furnished or will deliver to the Representatives and counsel for the Underwriters, without charge, signed copies of the Registration Statement as originally filed and of each amendment thereto (including exhibits filed therewith or incorporated by reference therein and documents incorporated or deemed to be incorporated by reference therein) and signed copies of all consents and certificates of experts, and will also deliver to the Representatives, without charge, a conformed copy of the Registration Statement as originally filed and of each amendment thereto (without exhibits) for each of the Underwriters. The copies of the Registration Statement and each amendment thereto furnished to the Underwriters will be identical to the electronically transmitted copies thereof filed with the Commission pursuant to ▇▇▇▇▇, except to the extent permitted by Regulation S-T.

(g)

Delivery of Prospectuses. The Company has delivered to each Underwriter, without charge, as many copies of each preliminary prospectus as such Underwriter reasonably requested, and the Company has delivered to each Underwriter, without charge, as many copies of each Issuer Free Writing Prospectus as such Underwriter reasonably requested, and the Company hereby consents to the use of such copies for purposes permitted by the Securities Act. The Company will furnish to each Underwriter, without charge, during the Prospectus Delivery Period, such number of copies of the Prospectus (as amended or supplemented) as such Underwriter may reasonably request. The Prospectus and any amendments or supplements thereto furnished to the Underwriters will be identical to the electronically transmitted copies thereof filed with the Commission pursuant to ▇▇▇▇▇, except to the extent permitted by Regulation S-T.

(h)

Blue Sky Qualifications. The Company will endeavor, in cooperation with the Underwriters, to qualify the Securities for offering and sale under the applicable securities laws of such states and other jurisdictions as the Representatives may designate and to maintain such qualifications in effect for a period of not less than one year from the later of the date hereof or such shorter period as is necessary to complete the distribution of the Securities; provided, however, that the Company shall not be obligated to file any general consent to service of process or to qualify as a foreign corporation or as a dealer in securities in any jurisdiction in which it is not so qualified or to subject itself to taxation in respect of doing business in any jurisdiction in which it is not otherwise so subject. In each jurisdiction in which the Securities have been so qualified, the Company will file such statements and reports as may be required by the laws of such jurisdiction to continue such qualification in effect for a period of not less than one year

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from the effective date of the Registration Statement and any Rule 462(b) Registration Statement. The Company will also supply the Underwriters with such information as is necessary for the determination of the legality of the Securities for investment under the laws of such jurisdictions as the Underwriters may request.

(i)

Rule 158. The Company will timely file such reports pursuant to the Exchange Act as are necessary in order to make generally available to its securityholders as soon as practicable an earnings statement for the purposes of, and to provide to the Underwriters the benefits contemplated by, the last paragraph of Section 11(a) of the Securities Act.

(j)

Use of Proceeds. The Company will use the net proceeds received by it from the sale of Securities in the manner specified in each of the Disclosure Package and the Prospectus under “Use of Proceeds.”

(k)

Restriction on Sale of Securities. During a period of 30 days from the date of the Prospectus, the Company will not, without the prior written consent of the Representatives, directly or indirectly, issue, sell, offer, pledge or contract to sell, grant any option, right or warrant for the sale of, lend or otherwise transfer or dispose of, any debt securities of the Company or any securities convertible into, or exercisable or exchangeable for, debt securities of the Company, other than such securities representing commercial bank debt or intercompany debt.

(l)

Reporting Requirements. The Company, during the Prospectus Delivery Period, will file all documents required to be filed with the Commission pursuant to the Exchange Act within the time periods required by the Exchange Act.

SECTION 4. Payment of Expenses.

(a)

Expenses. The Company will pay all expenses incident to the performance of its obligations under this Agreement, including (i) the preparation, printing and filing of the Registration Statement (including financial statements and exhibits) as originally filed and of each amendment thereto, (ii) the preparation, printing and delivery to the Underwriters of this Agreement, any Agreement among Underwriters, the Indenture and such other documents as may be required in connection with the offering, purchase, sale, issuance or delivery of the Securities, (iii) the preparation, issuance and delivery of the certificates, if any, for the Securities to the Underwriters, (iv) the fees and disbursements of the Company’s counsel, accountants and other advisors, (v) the qualification of the Securities under securities laws in accordance with the provisions of Section 3(h) hereof, including filing fees and the reasonable fees and disbursements of counsel for the Underwriters in connection therewith and in connection with the preparation of the Blue Sky Survey and any supplement thereto, (vi) the printing and delivery to the Underwriters of copies of each preliminary prospectus, any Issuer Free Writing Prospectus and of the Prospectus and any amendments or supplements thereto, (vii) the preparation, printing and delivery to the Underwriters of copies of the Blue Sky Survey and any supplement thereto, (viii) the fees and expenses of the Trustee, including the fees and disbursements of counsel for the Trustee in connection with the Indenture and the Securities, and (ix) any fees payable in connection with the rating of the Securities.

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(b)

Termination of Agreement. If this Agreement is terminated by the Representatives in accordance with the provisions of Section 5 or Sections 9(a)(i) or (a)(iii) (only with respect to the Company’s securities) hereof, the Company shall reimburse the Underwriters for all of their out-of-pocket expenses, including the reasonable fees and disbursements of counsel for the Underwriters.

SECTION 5. Conditions of Underwriters’ Obligations. The obligations of the several Underwriters hereunder are subject to the accuracy of the representations and warranties of the Company contained in Section 1 hereof or in certificates of any officer of the Company delivered pursuant to the provisions hereof, to the performance by the Company of its covenants and other obligations hereunder, and to the following further conditions:

(a)

Compliance with Registration Requirements; No Stop Order. For the period from and after effectiveness of this Agreement and prior to the Closing Time:

(i)

the Company shall have filed any preliminary prospectus and the Prospectus with the Commission (including the information required by Rule 430B under the Securities Act) in the manner and within the time period required by Rule 424(b) under the Securities Act; or the Company shall have filed a post-effective amendment to the Registration Statement containing the information required by such Rule 430B, and such post-effective amendment shall have become effective;

(ii)

the Final Term Sheet, and any other material required to be filed by the Company pursuant to Rule 433(d) under the Securities Act, shall have been filed with the Commission within the applicable time periods prescribed for such filings under such Rule 433; and

(iii)

no stop order suspending the effectiveness of the Registration Statement, or any post-effective amendment to the Registration Statement, shall be in effect and no proceedings for such purpose shall have been instituted or threatened by the Commission.

(b)

Opinion of ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇, Esq. At Closing Time, the Representatives shall have received the favorable opinion, dated as of Closing Time, of ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇, Esq, counsel for the Company, who may rely as to all matters governed by Federal and New York law upon the opinion of ▇▇▇▇▇▇▇, Arps, Slate, ▇▇▇▇▇▇▇ & ▇▇▇▇ LLP referred to below, in form and substance reasonably satisfactory to counsel for the Underwriters, to the effect that:

(i)

The Company has been duly incorporated and is an existing corporation in good standing under the laws of the State of Utah.

(ii)

The Company has corporate power and authority to own its properties and conduct its business as described in the Disclosure Package and the Prospectus; and the Company is duly qualified to do business as a foreign corporation and is in good standing in all other jurisdictions in which it owns or leases substantial properties or in which the conduct of its business requires such

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qualification, except where the failure to be so qualified would not have a Material Adverse Effect.

(iii)

The Securities are in the form contemplated by the Indenture, have been duly authorized by the Company and, assuming that the Securities have been duly authenticated by the Trustee in accordance with the terms of the Indenture, the Securities have been duly executed, issued and delivered by the Company and constitute valid and binding obligations of the Company, entitled to the benefits of the Indenture and enforceable against the Company in accordance with their terms, except to the extent that enforcement thereof may be limited by (a) bankruptcy, insolvency, reorganization, moratorium or other similar laws now or hereinafter in effect relating to or affecting creditors’ rights generally, (b) general principles of equity (regardless of whether enforceability is considered in a proceeding at law or in equity) and (c) the applicability or effect of any fraudulent transfer, preference or similar law. In expressing the opinion set forth in this paragraph (iii), such counsel may assume that the Securities, in the form delivered to the Underwriters, conform to the specimen of the Securities examined by such counsel, which fact need not be verified by an inspection of the individual Securities.

(iv)

The execution, delivery and performance of the Indenture and of this Agreement and the issuance and sale of the Securities and compliance with the terms and provisions hereof and thereof will not (a) result in a breach or violation of any of the terms or provisions of, or constitute a default under, (1) any order known to such counsel of any governmental agency having jurisdiction over the Company or any of its properties or any agreement or instrument known to such counsel to which the Company is a party or by which the Company is bound or to which any of the properties of the Company is subject, which would cause a material adverse change in the financial position, shareholders’ equity or results of operations of the Company or affect the validity of the Securities or the legal authority of the Company to comply with the terms of the Securities, the Indenture, this Agreement or (2) the charter or bylaws of the Company or (b) result in the creation or imposition of any lien, charge or encumbrance upon any property or assets of the Company or any subsidiary pursuant to any contract, indenture, mortgage, deed of trust, loan or credit agreement, note, lease or any other agreement or instrument, known to such counsel, to which the Company or any subsidiary is a party or by which it or any of them may be bound, or to which any of the property or assets of the Company or any subsidiary is subject (except for such liens, charges or encumbrances that would not have a Material Adverse Effect); and the Company has full power and authority to authorize, issue and sell the Securities as contemplated by this Agreement.

(v)

The Indenture has been duly authorized, executed and delivered by the Company and (assuming the due authorization, execution and delivery of the Indenture by the Trustee) is a valid and binding agreement of the Company, enforceable against the Company in accordance with its terms, except to the

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extent enforcement thereof may be limited by (a) bankruptcy, insolvency, reorganization, moratorium or other similar laws now or hereinafter in effect relating to or affecting creditors’ rights generally, (b) general principles of equity (regardless of whether enforceability is considered in a proceeding at law or in equity) and (c) the applicability or effect of any fraudulent transfer, preference or similar law.

(vi)

This Agreement has been duly authorized, executed and delivered by the Company.

(vii)

No authorization, approval or consent of any governmental authority or agency is necessary in connection with the transactions contemplated by this Agreement, except such as may be required under the Securities Act, the Trust Indenture Act, state securities or Blue Sky laws, and except as have been obtained.

(viii)

The documents incorporated by reference in the Disclosure Package and the Prospectus (other than the financial statements and supporting schedules included therein or omitted therefrom, as to which such counsel need express no opinion), when they were filed with the Commission complied as to form in all material respects with the requirements of the Exchange Act.

(ix)

Such counsel does not know of any contracts or documents required to be filed as exhibits to the Registration Statement which are not filed as required.

(x)

Such counsel does not know of any legal or governmental proceedings relating to regulatory matters of the type referred to in the Prospectus under the captions entitled "Questar Gas Company—The Company" and "Risk Factors—Risks Related to Our Business" pending to which the Company or any of its subsidiaries is a party or to which any of their property is subject that are required to be disclosed in the Registration Statement or the Prospectus pursuant to Item 103 of Regulation S-K of the Securities Act which are not so disclosed as required.

(c)

Opinion of Company Counsel. At Closing Time, the Representatives shall have received the favorable opinion, dated as of Closing Time, of ▇▇▇▇▇▇▇, Arps, Slate, ▇▇▇▇▇▇▇ & ▇▇▇▇ LLP, special counsel for the Company, in form and substance reasonably satisfactory to counsel for the Underwriters, to the effect that:

(i)

The Securities are in the form contemplated by the Indenture, and when duly authenticated by the Trustee and issued and delivered by the Company against payment therefor in accordance with the terms hereof will constitute valid and binding obligations of the Company, entitled to the benefits of the Indenture and enforceable against the Company in accordance with their terms, except to the extent that enforcement thereof may be limited by (a) bankruptcy, insolvency, reorganization, moratorium or other similar laws now or hereinafter in effect

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relating to or affecting creditors’ rights generally, (b) general principles of equity (regardless of whether enforceability is considered in a proceeding at law or in equity) and (c) the applicability or effect of any fraudulent transfer, preference or similar law.

(ii)

The Indenture has been duly executed and delivered by the Company (to the extent such execution and delivery are matters governed by the laws of the State of New York) and (assuming the due authorization, execution and delivery of the Indenture by the Trustee) is a valid and binding agreement of the Company, enforceable against the Company in accordance with its terms, except to the extent enforcement thereof may be limited by (a) bankruptcy, insolvency, reorganization, moratorium or other similar laws now or hereinafter in effect relating to or affecting creditors’ rights generally, (b) general principles of equity (regardless of whether enforceability is considered in a proceeding at law or in equity) and (c) the applicability or effect of any fraudulent transfer, preference or similar law.

(iii)

This Agreement has been duly executed and delivered by the Company (to the extent such execution and delivery are matters governed by the laws of the State of New York).

(iv)

The Registration Statement, at the time of the first contract of sale of the Securities, and the Prospectus, as of its date (but excluding the Form T-1 and the financial statements and the related notes, schedules and other financial or reserve data included or incorporated by reference in or excluded from the Registration Statement or the exhibits thereto, as to which such counsel need express no opinion), appeared on their face to be appropriately responsive in all material respects to the requirements of the Securities Act, as applicable, except that such counsel need not assume any responsibility for the accuracy, completeness or fairness of the statements contained or incorporated by reference in the Registration Statement or the Prospectus except to the extent set forth in paragraph (vii) herein.

(v)

Such counsel does not know of any legal or governmental proceedings pending to which the Company or any of its subsidiaries is a party or to which any of their property is subject that are required to be disclosed in the Registration Statement or the Prospectus pursuant to Item 103 of Regulation S-K of the Securities Act which are not so disclosed as required, except that such counsel need not express any opinion pursuant to this subparagraph (v) with respect to legal or governmental proceedings relating to regulatory matters of the type referred to in the Prospectus under the captions entitled "Questar Gas Company—The Company" and "Risk Factors—Risks Related to Our Business."

(vi)

No authorization, approval or consent of any governmental authority or agency which has not been obtained or taken and is not in full force and effect, is required to authorize, or is required for, the execution or delivery of

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this Agreement by the Company or the consummation by the Company of the transactions contemplated by this Agreement.

(vii)

The statements set forth in each of the preliminary prospectus and the Prospectus under the captions “Description of Notes” and “Description of Debt Securities,” insofar as such statements purport to summarize certain provisions of the Indenture and the Securities, fairly summarize such provisions in all material respects.

(viii)

The Company is not and, solely after giving effect to the offering and sale of the Securities and the application of the proceeds thereof as described in the Prospectus, will not be an “investment company” as such term is defined in the Investment Company Act.

(d)

Opinion of Counsel to the Underwriters. The Representatives shall have received from ▇▇▇▇▇▇ ▇▇▇▇▇▇ LLP, counsel to the Underwriters, such opinion or opinions, dated the Closing Time, with respect to the issuance and sale of the Securities, the Indenture, the Registration Statement, the Disclosure Package, the Prospectus and other related matters as the Representatives may reasonably require, and the Company shall have furnished to such counsel such documents as they request for the purpose of enabling them to pass upon such matters.

(e)

In giving their opinions as of the date hereof required by subsection (b), (c) and (d) of this Section, ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇, Esq., ▇▇▇▇▇▇▇, Arps, Slate, ▇▇▇▇▇▇▇ & ▇▇▇▇ LLP and ▇▇▇▇▇▇ ▇▇▇▇▇▇ LLP shall each additionally state that the Registration Statement has been declared effective by the Commission under the Securities Act, the Indenture was qualified under the Trust Indenture Act, and, to the best of such counsel’s knowledge, no stop order suspending the effectiveness of the Registration Statement or any post-effective amendment to the Registration Statement is in effect and no proceedings for such purpose have been instituted or are pending or, to the best of such counsel’s knowledge, are threatened by the Commission. In addition, each such counsel (other than ▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇▇▇) shall state that they have participated in conferences with officers and other representatives of the Company, representatives of the independent accountants of the Company, and representatives of the Underwriters, at which the contents of the Registration Statement, the Disclosure Package and the Prospectus and any amendments or supplements thereto, and related matters were discussed and, although such counsel are not passing upon, and do not assume any responsibility for, the accuracy, completeness or fairness of the statements contained in the Registration Statement, the Disclosure Package or the Prospectus (other than as specified above), and any supplements or amendments thereto, on the basis of the foregoing, no facts have come to their attention that have caused them to believe that (i) the Registration Statement or any amendments thereto, at the time of the first contract of sale of the Securities, contained an untrue statement of a material fact or omitted to state a material fact required to be stated therein or necessary in order to make the statements therein not misleading; (ii) the Prospectus, as of its date or at the Closing Time, contains or contained an untrue statement of a material fact or omits or omitted to state a material fact necessary in order to make the statements therein, in the light of the

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circumstances under which they were made, not misleading; or (iii) the Disclosure Package, as of the Applicable Time, contained any untrue statement of a material fact or omitted to state any material fact necessary in order to make the statements therein, in the light of circumstances under which they were made, not misleading (it being understood that such counsel need express no belief as to the financial statements and the related notes, schedules and other financial or reserve data included in or excluded from or incorporated by reference in the Registration Statement, the Prospectus, the Disclosure Package or any amendments or supplements thereto or statements contained in exhibits thereto, including the Form T-1).

(f)

Officers’ Certificate. At Closing Time, there shall not have been, since the date hereof or since the respective dates as of which information is given in the Prospectus or the Disclosure Package, any material adverse change in the condition, financial or otherwise, or in the earnings, business affairs or business prospects of the Company and its subsidiaries considered as one enterprise, whether or not arising in the ordinary course of business, and the Representatives shall have received a certificate of the President or a Vice President of the Company and of the chief financial or chief accounting officer of the Company, dated as of Closing Time, to the effect that (i) there has been no such material adverse change, (ii) the representations and warranties in Section 1 hereof are true and correct with the same force and effect as though expressly made at and as of Closing Time, (iii) the Company has complied with all covenants and agreements and satisfied all conditions on its part to be performed or satisfied at or prior to Closing Time, and (iv) no stop order suspending the effectiveness of the Registration Statement has been issued and no proceedings for that purpose have been instituted or are pending or, to the knowledge of the Company, are contemplated by the Commission.

(g)

Accountant’s Comfort Letter. At the time of the execution of this Agreement, the Representatives shall have received from Ernst & Young, LLP a letter dated such date, in form and substance satisfactory to the Representatives, together with signed or reproduced copies of such letter for each of the other Underwriters containing statements and information of the type ordinarily included in accountants’ “comfort letters” to underwriters with respect to the financial statements and certain financial information contained in the Registration Statement, the preliminary prospectus and the Prospectus.

(h)

Bring-down Comfort Letter. At Closing Time, the Representatives shall have received from Ernst & Young, LLP a letter, dated as of Closing Time, to the effect that they reaffirm the statements made in the letter furnished pursuant to subsection (g) of this Section, except that the specified date referred to shall be a date not more than three business days prior to Closing Time.

(i)

Maintenance of Rating. At Closing Time, the Securities shall be rated at least A3 by ▇▇▇▇▇’▇ Investors Service Inc. and A- by Standard & Poor’s Ratings Services, a division of ▇▇▇▇▇▇-▇▇▇▇, Inc., and, if requested, the Company shall have delivered to the Representatives a letter dated the Closing Time, from each such rating agency, or other evidence satisfactory to the Representatives, confirming that the Securities have such ratings; and since the date of this Agreement, there shall not have

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occurred a downgrading in the rating assigned to the Securities or any of the Company’s other debt securities by any “nationally recognized statistical rating agency,” as that term is defined by the Commission for purposes of Rule 436(g)(2) under the Securities Act, and no such organization shall have publicly announced that it has under surveillance or review its rating of the Securities or any of the Company’s other debt securities.

(j)

Additional Documents. At Closing Time, counsel for the Underwriters shall have been furnished with such documents and opinions as they may reasonably require for the purpose of enabling them to pass upon the issuance and sale of the Securities as herein contemplated, or in order to evidence the accuracy of any of the representations or warranties, or the fulfillment of any of the conditions, herein contained; and all proceedings taken by the Company in connection with the issuance and sale of the Securities as herein contemplated shall be reasonably satisfactory in form and substance to the Representatives and counsel for the Underwriters.

(k)

Termination of Agreement. If any condition specified in this Section shall not have been fulfilled when and as required to be fulfilled, this Agreement may be terminated by the Representatives by notice to the Company at any time at or prior to Closing Time, and such termination shall be without liability of any party to any other party except as provided in Section 4 and except that Sections 1, 6, 7 and 8 shall survive any such termination and remain in full force and effect.

SECTION 6. Indemnification.

(a)

Indemnification of Underwriters. The Company agrees to indemnify and hold harmless each Underwriter and each person, if any, who controls any Underwriter within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act as follows:

(i)

against any and all loss, liability, claim, damage and expense whatsoever, as incurred, arising out of any untrue statement or alleged untrue statement of a material fact contained in the Registration Statement (or any amendment thereto), including, without limitation, the Rule 430B Information, or the omission or alleged omission therefrom of a material fact required to be stated therein or necessary to make the statements therein not misleading or arising out of any untrue statement or alleged untrue statement of a material fact contained in the Disclosure Package or the Prospectus (or any amendment or supplement thereto), or the omission or alleged omission therefrom of a material fact necessary in order to make the statements therein, in the light of the circumstances under which they were made, not misleading;

(ii)

against any and all loss, liability, claim, damage and expense whatsoever, as incurred, to the extent of the aggregate amount paid in settlement of any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or of any claim whatsoever based upon any such untrue statement or omission, or any such alleged untrue statement or omission; provided that (subject to Section 6(d) below) any such settlement is effected with the written consent of the Company; and

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(iii)

against any and all expense whatsoever, as incurred (including, subject to Section 6(c) hereof, the fees and disbursements of counsel chosen by the Representatives), reasonably incurred in investigating, preparing or defending against any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or any claim whatsoever based upon any such untrue statement or omission, or any such alleged untrue statement or omission, to the extent that any such expense is not paid under (i) or (ii) above;

provided, however, that this indemnity agreement shall not apply to any loss, liability, claim, damage or expense to the extent arising out of any untrue statement or omission or alleged untrue statement or omission made in reliance upon and in conformity with written information furnished to the Company by any Underwriter through the Representatives expressly for use in the Registration Statement (or any amendment thereto), the Disclosure Package or the Prospectus (or any amendment or supplement thereto). The foregoing indemnity shall not inure to the benefit of any Underwriter from whom the person asserting any such losses, claims, damages or liabilities purchased the Securities, or any person controlling such Underwriter, where it shall have been determined by a court of competent jurisdiction by final and nonappealable judgment that (i) prior to the Applicable Time the Company shall have notified such Underwriter in writing that the Disclosure Package contains an untrue statement of material fact or omits to state therein a material fact required to be stated therein in order to make the statements therein not misleading, (ii) such untrue statement or omission of a material fact was corrected in an amendment or supplement to the Disclosure Package and such amendment or supplement was provided to such Underwriter at least twenty-four hours prior to the Applicable Time and, to the extent that physical delivery is required, in sufficient quantity so that such amendment or supplement could have been conveyed to such person prior to the Applicable Time, (iii) the information contained in such amendment or supplement was not conveyed to such person at or prior to the Applicable Time with respect to such person and (iv) such loss, claim, damage or liability would not have occurred had such amendment or supplement been conveyed to such person.

(b)

Indemnification of Company, Directors and Officers. Each Underwriter severally agrees to indemnify and hold harmless the Company, its directors, each of its officers who signed the Registration Statement, 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 against any and all loss, liability, claim, damage and expense described in the indemnity contained in subsection (a) of this Section, as incurred, but only with respect to untrue statements or omissions, or alleged untrue statements or omissions, made in the Registration Statement (or any amendment thereto), including, without limitation, the Rule 430B Information, the Disclosure Package or the Prospectus (or any amendment or supplement thereto) in reliance upon and in conformity with written information furnished to the Company by such Underwriter through the Representatives expressly for use therein, and will reimburse any legal or other expenses reasonably incurred by the Company in connection with investigating or defending such loss, liability, claim, damage, expense or action as such expenses are incurred.

(c)

Actions against Parties; Notification. Each indemnified party shall give notice as promptly as reasonably practicable to each indemnifying party of any action commenced against it in respect of which indemnity may be sought hereunder, but failure to so notify an

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indemnifying party shall not relieve such indemnifying party from any liability hereunder to the extent it is not materially prejudiced as a result thereof and in any event shall not relieve it from any liability which it may have otherwise than on account of this indemnity agreement. In the case of parties indemnified pursuant to Section 6(a) above, counsel to the indemnified parties shall be selected by the Representatives, and, in the case of parties indemnified pursuant to Section 6(b) above, counsel to the indemnified parties shall be selected by the Company. If it so elects within a reasonable time after receipt of such notice, an indemnifying party, jointly with any other indemnifying parties receiving such notice, may assume the defense of such action with counsel chosen by it and approved by the indemnified parties defendant in such action (which approval shall not be unreasonably withheld), unless such indemnified parties reasonably object to such assumption on the ground that there may be legal defenses available to them which are different from or in addition to those available to such indemnifying party. If an indemnifying party assumes the defense of such action, the indemnifying party shall not be liable for any fees and expenses of counsel for the indemnified parties incurred thereafter in connection with such action other than the reasonable costs of investigation. In no event shall the indemnifying parties be liable for fees and expenses of more than one counsel (in addition to any local counsel) separate from their own counsel for all indemnified parties in connection with any one action or separate but similar or related actions in the same jurisdiction arising out of the same general allegations or circumstances. No indemnifying party shall, without the prior written consent of the indemnified parties, settle or compromise or consent to the entry of any judgment with respect to any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or any claim whatsoever in respect of which indemnification or contribution could be sought under this Section 6 or Section 7 hereof (whether or not the indemnified parties are actual or potential parties thereto), unless such settlement, compromise or consent (i) includes an unconditional release of each indemnified party from all liability arising out of such litigation, investigation, proceeding or claim 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)

Settlement without Consent if Failure to Reimburse. If at any time an indemnified party shall have requested an indemnifying party to reimburse the indemnified party for fees and expenses of counsel, such indemnifying party agrees that it shall be liable for any settlement of the nature contemplated by Section 6(a)(ii) effected without its written consent if (i) such settlement is entered into more than 45 days after receipt by such indemnifying party of the aforesaid request, (ii) such indemnifying party shall have received notice of the terms of such settlement at least 30 days prior to such settlement being entered into and (iii) such indemnifying party shall not have reimbursed such indemnified party in accordance with such request prior to the date of such settlement. Notwithstanding the immediately preceding sentence, if at any time an indemnified party shall have requested an indemnifying party to reimburse the indemnified party for fees and expenses of counsel, an indemnifying party shall not be liable for any settlement of the nature contemplated by Section 6(a)(ii) effected without its consent if such indemnifying party (i) reimburses such indemnified party in accordance with such request to the extent it considers such request to be reasonable and (ii) provides written notice to the indemnified party substantiating the unpaid balance as unreasonable, in each case prior to the date of such settlement.

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SECTION 7. Contribution. If the indemnification provided for in Section 6 hereof is for any reason (except as provided therein) unavailable to or insufficient to hold harmless an indemnified party in respect of any losses, liabilities, claims, damages or expenses referred to therein, then each indemnifying party shall contribute to the aggregate amount of such losses, liabilities, claims, damages and expenses incurred by such indemnified party, as incurred, (i) in such proportion as is appropriate to reflect the relative benefits received by the Company on the one hand and the Underwriters on the other hand from the offering of the Securities pursuant to this Agreement or (ii) if the allocation provided by 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 Company on the one hand and of the Underwriters on the other hand in connection with the statements or omissions which resulted in such losses, liabilities, claims, damages or expenses, as well as any other relevant equitable considerations.

The relative benefits received by the Company on the one hand and the Underwriters on the other hand in connection with the offering of the Securities pursuant to this Agreement shall be deemed to be in the same respective proportions as the total net proceeds from the offering of the Securities pursuant to this Agreement (before deducting expenses) received by the Company and the total underwriting discount received by the Underwriters, in each case as set forth on the cover of the Prospectus, bear to the aggregate initial public offering price of the Securities as set forth on such cover.

The relative fault of the Company on the one hand and the Underwriters on the other hand shall be determined by reference to, among other things, whether any such untrue or alleged untrue statement of a material fact or omission or alleged omission to state a material fact relates to information supplied by the Company or by the Underwriters and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission.

The Company and the Underwriters agree that it would not be just and equitable if contribution pursuant to this Section 7 were determined by pro rata allocation (even if the Underwriters were treated as one entity for such purpose) or by any other method of allocation which does not take account of the equitable considerations referred to above in this Section 7. The aggregate amount of losses, liabilities, claims, damages and expenses incurred by an indemnified party and referred to above in this Section 7 shall be deemed to include any legal or other expenses reasonably incurred by such indemnified party in investigating, preparing or defending against any litigation, or any investigation or proceeding by any governmental agency or body, commenced or threatened, or any claim whatsoever based upon any such untrue or alleged untrue statement or omission or alleged omission.

Notwithstanding the provisions of this Section 7, no Underwriter shall be required to contribute any amount in excess of the amount by which the total price at which the Securities underwritten by it and distributed to the public were offered to the public exceeds the amount of any damages which such Underwriter has otherwise been required to pay by reason of any such untrue or alleged untrue statement or omission or alleged omission.

SF1 1490185v.6

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 Section 7, each person, if any, who controls an Underwriter within the meaning of Section 15 of the Securities Act or Section 20 of the Exchange Act shall have the same rights to contribution as such Underwriter, and each director of the Company, each officer of the Company who signed the Registration Statement, 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 shall have the same rights to contribution as the Company. The Underwriters’ respective obligations to contribute pursuant to this Section 7 are several in proportion to the principal amount of Securities set forth opposite their respective names in Schedule A hereto and not joint.

SECTION 8. Representations, Warranties and Agreements to Survive Delivery. All representations, warranties and agreements contained in this Agreement or in certificates of officers of the Company or any of its subsidiaries submitted pursuant hereto, shall remain operative and in full force and effect, regardless of any investigation made by or on behalf of any Underwriter or controlling person, or by or on behalf of the Company, and shall survive delivery of the Securities to the Underwriters.

SECTION 9. Termination of Agreement.

(a)

Termination; General. The Representatives may terminate this Agreement, by notice to the Company, at any time at or prior to Closing Time (i) if there has been, since the time of execution of this Agreement or since the respective dates as of which information is given in the Prospectus or the Disclosure Package, any material adverse change in the condition, financial or otherwise, or in the earnings, business affairs or business prospects of the Company and its subsidiaries considered as one enterprise, whether or not arising in the ordinary course of business, or (ii) if there has occurred any material adverse change in the financial markets in the United States or any outbreak of hostilities or escalation thereof or other calamity or crisis, in each case the effect of which is such as to make it, in the reasonable judgment of the Representatives, impracticable or inadvisable to market the Securities or to enforce contracts for the sale of the Securities, or (iii) if trading in the securities of the Company has been suspended or materially limited by the Commission, or if trading generally on the American Stock Exchange or the New York Stock Exchange or in the NASDAQ Global Market has been suspended or materially limited, or minimum or maximum prices for trading have been fixed, or maximum ranges for prices have been required, by any of the exchanges or by such system or by order of the Commission, the Financial Industry Regulatory Authority or any other governmental authority, or (iv) if a banking moratorium has been declared by either Federal, New York or Utah authorities, or (v) there has occurred a material disruption in commercial banking or securities settlement or clearance services.

(b)

Liabilities. If this Agreement is terminated pursuant to this Section, such termination shall be without liability of any party to any other party except as provided in Section 4 hereof, and provided further that Sections 1, 6, 7 and 8 shall survive such termination and remain in full force and effect.

SF1 1490185v.6

SECTION 10. Default by One or More of the Underwriters. If one or more of the Underwriters shall fail at Closing Time to purchase the Securities which it or they are obligated to purchase under this Agreement (the “Defaulted Securities”), the Representatives shall have the right, within 24 hours thereafter, to make arrangements for one or more of the non-defaulting Underwriters, or any other underwriters, to purchase all, but not less than all, of the Defaulted Securities in such amounts as may be agreed upon and upon the terms herein set forth; if, however, the Representatives shall not have completed such arrangements within such 24-hour period, then:

(a)

if the number of Defaulted Securities does not exceed 10% of the aggregate principal amount of the Securities to be purchased hereunder, each of the non-defaulting Underwriters shall be obligated, severally and not jointly, to purchase the full amount thereof in the proportions that their respective underwriting obligations hereunder bear to the underwriting obligations of all non-defaulting Underwriters, or

(b)

if the number of Defaulted Securities exceeds 10% of the aggregate principal amount of the Securities to be purchased hereunder, this Agreement shall terminate without liability on the part of any non-defaulting Underwriter.

No action taken pursuant to this Section shall relieve any defaulting Underwriter from liability in respect of its default.

In the event of any such default which does not result in a termination of this Agreement, either the Representatives or the Company shall have the right to postpone Closing Time for a period not exceeding seven days in order to effect any required changes in the Registration Statement or Prospectus or in any other documents or arrangements. As used herein, the term “Underwriter” includes any person substituted for an Underwriter under this Section 10.

SECTION 11. Notices. All notices and other communications hereunder shall be in writing and shall be deemed to have been duly given if mailed or transmitted by any standard form of telecommunication. Notices to the Underwriters shall be directed to the Representatives at Barclays Capital Inc., ▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇, Attention: Fixed Income Syndicate, 5^th Floor, Facsimile (▇▇▇) ▇▇▇-▇▇▇▇ and ▇.▇. ▇▇▇▇▇▇ Securities Inc., ▇▇▇ ▇▇▇▇ ▇▇▇▇▇▇, ▇▇▇ ▇▇▇▇, ▇▇▇ ▇▇▇▇ ▇▇▇▇▇, Attention: High Grade Syndicate Desk, 8^th Floor, Facsimile (▇▇▇) ▇▇▇-▇▇▇▇; and notices to the Company shall be directed to it at ▇▇▇ ▇▇▇▇ ▇▇▇ ▇▇▇▇▇, ▇.▇. Box 45433, Salt Lake City, Utah, 84145-0433, attention of ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇, Vice President and Chief Financial Officer.

SECTION 12. Parties. This Agreement shall each inure to the benefit of and be binding upon the Underwriters and the Company and their respective successors. Nothing expressed or mentioned in this Agreement is intended or shall be construed to give any person, firm or corporation, other than the Underwriters and the Company and their respective successors and the controlling persons and officers and directors referred to in Sections 6 and 7 and their heirs and legal representatives, any legal or equitable right, remedy or claim under or in respect of this Agreement or any provision herein contained. This Agreement and all conditions and provisions hereof are intended to be for the sole and exclusive benefit of the Underwriters and the Company and their respective successors, and the controlling persons and officers and directors and their

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heirs and legal representatives, and for the benefit of no other person, firm or corporation. No purchaser of Securities from any Underwriter shall be deemed to be a successor by reason merely of such purchase.

SECTION 13. No Advisory or Fiduciary Responsibility. The Company acknowledges and agrees that: (i) the purchase and sale of the Securities pursuant to this Agreement, including the determination of the public offering price of the Securities and any related discounts and commissions, is an arm’s-length commercial transaction between the Company, on the one hand, and the several Underwriters, on the other hand, 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; (ii) in connection with each transaction contemplated hereby and the process leading to such transaction each Underwriter is and has been acting solely as a principal and is not the financial advisor, agent or fiduciary of the Company or its affiliates, stockholders, creditors or employees or any other party; (iii) no Underwriter has assumed or will assume an advisory, agency or fiduciary responsibility in favor of the Company with respect to any of the transactions contemplated hereby or the process leading thereto (irrespective of whether such Underwriter has advised or is currently advising the Company on other matters) and no Underwriter has any obligation to the Company with respect to the offering contemplated hereby except the obligations expressly set forth in this Agreement; (iv) the several Underwriters and their respective affiliates may be engaged in a broad range of transactions that involve interests that differ from those of the Company and that the several Underwriters have no obligation to disclose any of such interests by virtue of any advisory, agency or fiduciary relationship; and (v) the Underwriters have not provided any legal, accounting, regulatory or tax advice with respect to the offering contemplated hereby and the Company has consulted its own legal, accounting, regulatory and tax advisors to the extent it deemed appropriate.

This Agreement supersedes all prior agreements and understandings (whether written or oral) between the Company and the several Underwriters, or any of them, with respect to the subject matter hereof. The Company hereby waives and releases, to the fullest extent permitted by law, any claims that the Company may have against the several Underwriters with respect to any breach or alleged breach of agency or fiduciary duty.

SECTION 14. GOVERNING LAW AND TIME. THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK. SPECIFIED TIMES OF DAY REFER TO NEW YORK CITY TIME.

SECTION 15. Effect of Headings. The Article and Section headings herein and the Table of Contents are for convenience only and shall not affect the construction hereof.

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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 between the Underwriters and the Company in accordance with its terms.

Very truly yours,

QUESTAR GAS COMPANY

By:

/s/ ▇▇▇▇ ▇. ▇▇▇▇▇▇

▇▇▇▇ ▇. ▇▇▇▇▇▇
President and Chief Executive Officer

CONFIRMED AND ACCEPTED,
as of the date first above written:

BARCLAYS CAPITAL INC.

By:

/s/ ▇▇▇▇▇ ▇▇▇▇▇▇▇▇

Authorized Signatory

▇.▇. ▇▇▇▇▇▇ SECURITIES INC.

/s/ ▇▇▇▇▇▇▇ ▇. ▇▇▇▇▇▇▇

Authorized Signatory

For themselves and as Representatives of the other Underwriters named in Schedule A hereto.

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SCHEDULE A


Name of Underwriter	Principal Amount of Notes due 2018	Principal Amount of Notes due 2038

Barclays Capital Inc.	$ 17,500,000	$ 35,000,000
▇.▇. ▇▇▇▇▇▇ Securities Inc.	17,500,000	35,000,000
Lazard Capital Markets LLC	5,000,000	10,000,000
Greenwich Capital Markets, Inc.	5,000,000	10,000,000
Wachovia Capital Markets, LLC	5,000,000	10,000,000
Total	$ 50,000,000	$100,000,000

Sch. A-1

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SCHEDULE B

Questar Gas Company
Final Term Sheet
March 24, 2008

Issuer:

Questar Gas Company

Aggregate Principal Amount Offered:

$50,000,000

Coupon:

6.300%

Maturity:

April 1, 2018

Yield to Maturity:

6.308%

Spread to Benchmark Treasury:

+ 275 basis points

Benchmark Treasury:

3.500% due Feb. 15, 2018

Benchmark Treasury Price and Yield:

99-16+ and 3.558%

Interest Payment Dates:

April 1 and October 1, commencing October 1, 2008

Redemption Provision:

Make Whole Call UST + 45 basis points

Price to Public:

99.940%

Settlement Date:

March 27, 2008

Book-runners:

Barclays Capital Inc. and ▇.▇. ▇▇▇▇▇▇ Securities Inc.

Co-managers:

Lazard Capital Markets LLC, Greenwich Capital Markets, Inc., Wachovia Capital Markets, LLC

The issuer has filed a registration statement (including a prospectus) with the SEC for the offering to which this communication relates. Before you invest, you should read the prospectus in that registration statement and other documents the issuer has filed with the SEC for more complete information about the issuer and this offering. You may get these documents for free by visiting ▇▇▇▇▇ on the SEC website at ▇▇▇.▇▇▇.▇▇▇. Alternatively, Barclays Capital Inc. or ▇.▇. ▇▇▇▇▇▇ Securities Inc. can arrange to send you the prospectus if you request it by calling Barclays Capital Inc. toll free at ▇-▇▇▇-▇▇▇-▇▇▇▇, extension 2663, or calling ▇.▇. ▇▇▇▇▇▇ Securities Inc. collect at ▇-▇▇▇-▇▇▇-▇▇▇▇.

Sch. B-1

SF1 1490185v.6

Questar Gas Company
Final Term Sheet
March 24, 2008

Issuer:

Questar Gas Company

Aggregate Principal Amount Offered:

$100,000,000

Coupon:

7.200%

Maturity:

April 1, 2038

Yield to Maturity:

7.205%

Spread to Benchmark Treasury:

+ 285 basis points

Benchmark Treasury:

5.000% due May 15, 2037

Benchmark Treasury Price and Yield:

110-18+ and 4.355%

Interest Payment Dates:

April 1 and October 1, commencing October 1, 2008

Redemption Provision:

Make Whole Call UST + 45 basis points

Price to Public:

99.937%

Settlement Date:

March 27, 2008

Book-runners:

Barclays Capital Inc. and ▇.▇. ▇▇▇▇▇▇ Securities Inc.

Co-managers:

Lazard Capital Markets LLC, Greenwich Capital Markets, Inc., Wachovia Capital Markets, LLC

Sch. B-2

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SCHEDULE C

Final Term Sheet dated March 24, 2008

Sch. C-1

SF1 1490185v.6

150,000,000 QUESTAR GAS COMPANY (a Utah corporation) $50,000,000 6.30% Notes due 2018 $100,000,000 7.20% Notes due 2038 PURCHASE AGREEMENT

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