8-K

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C.  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 reported):  February [20], 2007

ULTRA PETROLEUM CORP.

(Exact name of registrant as specified in its charter)

Yukon Territory, Canada	0-29370	N/A
(State or other jurisdiction of incorporation)	(Commission File Number)	(I.R.S. Employer Identification No.)

363 N. Sam Houston Parkway East

Suite 1200

Houston, Texas  77060

(Address of principal executive offices, including zip code)

Registrant’s telephone number, including area code:  (281) 876-0120

(Former name or former 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:

o Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

o Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

o Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

o Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 8.01.          Other Events

          Ultra Petroleum Corp. (the “Company”) issued a news release today announcing the Company’s 2006 proved reserve and production levels.  The press release is attached to this Report as Exhibit 99.1.

Item 9.01.          Financial Statements and Exhibits

                    (d)     Exhibits

Exhibit No.	Description
99.1	News Release dated February 20, 2007.

SIGNATURES

          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.

	ULTRA PETROLEUM CORP.
February 20, 2007	By:	/s/ Michael D. Watford
	Name:	Michael D. Watford
	Title:	Chairman, President and Chief
		Executive Officer

EXHIBIT INDEX

Exhibit No.	Description
99.1	News Release dated February 20, 2007

EX-99.1

Exhibit 99.1

NEWS RELEASE

FOR IMMEDIATE RELEASE

ULTRA PETROLEUM REPORTS 2006 PROVED RESERVES AND
RESERVE REPLACEMENT RATIO GREATER THAN 500%

• 2006 Reserve replacement ratio of 501 percent

• Proved reserves increase by 18 percent to 2.389 Tcfe

• 3P reserves of 9.945 Tcfe

• 100 percent success in 2006 Wyoming drilling

HOUSTON, Texas – February 20, 2007 – Ultra Petroleum Corp. (AMEX: UPL) today announced that it replaced 501 percent of 2006 production as of the year-ended December 31, 2006. Its total proved oil and gas reserves were 2.389 trillion cubic feet of gas equivalent (Tcfe), up 18 percent from 2.022 Tcfe as of December 31, 2005. Year-end 2006 proved reserves include 2.258 Tcf of natural gas and 21.80 million barrels of oil (Mmbbls). The estimated future net revenue from proved reserves discounted at 10 percent (“SEC PV-10”) is $2.782 billion based on weighted average prices at December 31, 2006, of $4.50 per Mcf for natural gas and $59.96 per bbl for crude oil. All reserves were prepared by Ultra Petroleum’s third party independent reserve consultants. Based on $7.00 per mcf sensitivity analysis for proved reserves at year-end the PV-10 value increases to $5.098 billion. Only those locations included in the company’s budgeted three-year drilling plan are included as proved undeveloped reserves in the report. Locations that are not in the three-year budget, but would otherwise be classified as proved are included in the probable and possible category. For the 8^th consecutive year Wyoming reserve estimates were prepared by the independent reservoir engineering firm of Netherland, Sewell and Associates, Inc.

“In 2006 Ultra Petroleum replaced 501 percent of our oil and gas production at a very attractive finding and development cost of $1.10 per Mcfe. Our development program delivered another strong year of performance with proven plus probable reserves now exceeding 6.5 Tcfe. More importantly, the third party identified, engineered, and economic resource base in Wyoming is now measured to be approximately 10 Tcfe net to Ultra Petroleum. Our inventory of low risk, high rate of return natural gas drilling locations continues to grow. Year-end 2006 undrilled locations grew by 90 percent to approximately 4,800 locations. At forecasted 2007 capital expenditure levels, our inventory totals 27 years,” commented Michael D. Watford, Chairman, President and Chief Executive Officer.

Ultra Petroleum Corp.	Page 1 of 3
2006 Reserves

Ultra Petroleum Corp.
Reserves
December 31, 2006

SEC Pricing - $4.50 per Mcf

Reserve Category	Net Gas (BCF)		Net Oil (MMB)		Net Equiv. (BCFE)		PV10 (MM$)		Economic Wells		Future Capex (MM$)
PDP		806.506		7.878		853.774	$	1,502.402		526	$	1.284
PDNP		36.463		1.329		44.439	$	80.427		32	$	16.242
PUD		1,415.132		12.622		1,490.864	$	1,199.618		536	$	1,663.282
Total Proved		2,258.101		21.829		2,389.077	$	2,782.447		1,094	$	1,680.808

Prepared by Netherland, Sewell and Associates, Inc. and Ryder Scott Company

Ultra Petroleum Corp.
Reserves
December 31, 2006

Natural Gas Sensitivity - $7.00 per Mcf

Reserve Category	Net Gas (BCF)		Net Oil (MMB)		Net Equiv. (BCFE)		PV10 (MM$)		Economic Wells		Future Capex (MM$)
PDP		822.129		7.993		870.089	$	2,335.261		528	$	1.284
PDNP		36.463		1.329		44.439	$	123.219		32	$	16.242
PUD		1,449.826		12.899		1,527.222	$	2,639.909		562	$	1,739.513
Total Proved		2,308.418		22.221		2,441.750	$	5,098.389		1,122	$	1,757.039
Probable		3,900.752		33.219		4,100.068	$	3,301.543		1,997	$	6,816.348
2P (PV. + PB.)		6,209.170		55.440		6,541.818	$	8,399.932		3,119	$	8,573.387
Possible		3,246.981		25.976		3,402.837	$	1,304.738		2,316	$	7,451.321
3P (PV. + PB. + PS.)		9,456.151		81.416		9,944.655	$	9,704.670		5,435	$	16,024.708

Prepared by Netherland, Sewell and Associates, Inc. and Ryder Scott Company

Ultra Petroleum Corp.	Page 2 of 3
2006 Reserves

About Ultra Petroleum

Ultra Petroleum is an independent, exploration and production company focused on developing its long-life natural gas reserves in the Green River Basin of Wyoming, and oil reserves in Bohai Bay, offshore China. Ultra Petroleum is listed on the American Stock Exchange under the symbol “UPL” with 151,795,633 shares outstanding as at December 31, 2006.

This release can be found at http://www.ultrapetroleum.com

This news release contains “forward-looking statements” as defined by the Securities and Exchange Commission. The opinions, forecast, projections, or statements other than those of historical fact, are forward-looking statements. Although the Company believes that the expectations reflected in the forward-looking statements are based on reasonable assumptions, it can give no assurance that such expectations will prove to have been correct and undertakes no obligation to update this information. The Company urges investors to consider that these statements are not guarantees of performance and that actual results could and may differ materially from these forward-looking statements. 

The SEC permits oil and gas companies, in their SEC filings, to disclose only “proved” reserves that the company has demonstrated to be economically and legally producible under existing economic and operating conditions by actual production or conclusive formation tests. Any reserve estimates in this press release that are not specifically designated as “proved” reserves may include not only proved reserves, but also other categories of reserves that the SEC guidelines allow in news releases but strictly prohibit the Company from including in its SEC filings. Investors are urged to consider this disclosure and additional disclosure in the Company’s Annual Report on Form 10-K, available on its website or by request to 363 North Sam Houston Parkway E., Suite 1200, Houston, 77060 (Attention: Investor Relations). You can also obtain this information from the SEC by calling 1-800-SEC-0330 or on its website at www.sec.gov.

For more information contact:

Kelly L. Whitley

Manager Investor Relations

Phone: 281-876-0120 Extension 302

Email: info@ultrapetroleum.com

Website: www.ultrapetroleum.com

Ultra Petroleum Corp.	Page 3 of 3
2006 Reserves