UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of Report (Date of earliest event reports): October 11, 2017

Questar Gas Company

(Exact name of registrant as specified in its charter)

Registrant’s telephone number, including area code: (801) 324-5900

Not Applicable

(Former name or address, if changed since last report)

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

Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§240.12b-2 of this chapter).

Emerging Growth Company  ☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.  ☐

On October 11, 2017, Questar Gas Company (the “Company”) entered into a Note Purchase Agreement (the “Note Purchase Agreement”) with the purchasers listed on Schedule A thereto (collectively, the “Purchasers”) relating to the issuance and sale by the Company of (i) $100,000,000 aggregate principal amount of 2017 Series A 3.38% Senior Notes due November 15, 2032; (ii) $50,000,000 aggregate principal amount of 2018 Series A 3.30% Senior Notes due April 1, 2030; and (iii) $100,000,000 aggregate principal amount of 2018 Series B 3.97% Senior Notes due November 15, 2047 (collectively, the “Notes”).

The Note Purchase Agreement contains restrictive covenants customary for similar financings, including, among other things, covenants that place limits on the Company’s ability to enter into material transactions with affiliates, merge or consolidate with other persons, incur liens on assets and incur additional debt. The Note Purchase Agreement also contains events of default customary for similar financings, the occurrence of which would permit the Purchasers to accelerate the amounts due under the Notes under certain circumstances.

The foregoing description of the Note Purchase Agreement is qualified in its entirety by reference to the Note Purchase Agreement, which is filed as Exhibit 1.1 hereto and incorporated herein by reference.

Item 2.03 Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant.

The information set forth in Item 1.01 above is hereby incorporated by reference into this Item 2.03.

SIGNATURE

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

Date: October 17, 2017