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 June 30, 2003, 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: August 7, 2003                      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.