Dominion Questar 10-Q 2003 Q1 Quarterly report

Exhibit 99.1

CERTIFICATION PURSUANT TO
18 U.S.C. SECTION 1350,
AS ADOPTED PURSUANT TO
SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Questar Corporation (the “Company”) on Form 10-Q for the period ending March 31, 2003, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), Keith O. Rattie, President and Chief Executive Officer of the Company, and S. E. Parks, Senior Vice President, Treasurer and Chief Financial Officer of the Company, each hereby certifies, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that, to the best of his knowledge:

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

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

	QUESTAR CORPORATION
May 13, 2003	/s/ Keith O. Rattie
	Keith O. Rattie
	President and Chief Executive Officer
May 13, 2003	/s/ S. E. Parks
	S. E. Parks
	Senior Vice President, Treasurer and Chief Financial Officer

A signed original of this written statement required by Section 906 has been provided to the Company and will be retained by the Company and furnished to the Securities and Exchange Commission or its staff upon request.

This certification accompanies the Report pursuant to Section 906 of the Sarbanes-Oxley Act of 2002 and shall not, except to the extent required by the Sarbanes-Oxley Act of 2002, be deemed filed by the Company for purposes of  Section 18 of the Securities Exchange Act of 1934, as amended.