Exhibit 32.1

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 Ultra Petroleum Corp. (the “Company”) on Form 10-Q for the period ended September 30, 2004, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Michael D. Watford, Chairman, Chief Executive Officer and President of the Company, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, to the best of my knowledge, that:

(1)	The Report fully complies with the requirements of Section 13(a) or 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.

Date: October 26, 2004	By:	/s/ Michael D. Watford
		Michael D. Watford
		Chairman, Chief Executive Officer and President

This certification is being furnished solely for purposes of compliance with 18 U.S.C. Section 1350 and shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that Section. Registration Statements or other documents filed with the Securities and Exchange Commission shall not incorporate this exhibit by reference, except as otherwise expressly stated in such filing.

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