Tri-Valley Expands Operations at Sunrise-Mayel.

Business Editors

BAKERSFIELD, Calif.--(BUSINESS WIRE)--March 6, 2003

Tri-Valley Corporation announced today that it is expanding operations at its Sunrise-Mayel No. 2H natural gas well near Delano, California to the upper Shafter-Wasco zone of the McClure Shale formation. The company has moved beyond its current zone, which has a significant amount of clay content that can swell and block gas delivery. The content of the formation surrounding the 3,100 feet of horizontal wellbore apparently reduced the effectiveness of the horizontal fracture process and commercial rates of production were not readily achievable at this time. However, the upper zone is deemed more likely to produce at commercial rates, as subsequent data shows it has far less clay content.

The new location will require another horizontal bore in this upper zone. Tri-Valley plans to return to the first zone tested at a later date after pursuing the more immediate opportunity contained in the upper zone. The location also contains three other zones that bring the total to nearly 300 net feet of gas-charged zones.

"We believe that this new location has tremendous potential," said F. Lynn Blystone, president and chief executive officer of Tri-Valley Corporation. "The Sunrise Natural Gas Project is most intriguing because of the immense amount of gas calculated to be in place in the tight McClure Shale zones from the two discovery and test wells. Enabling the gas to be liberated at commercial rates is an engineering task to deal with the unique fact that California, to the best of our knowledge, has the only producing diatomite formations in the world. However, that production can be prolific."

The Company's 8,300-acre lease covers approximately 6,600 acres of mapped closure which Tri-Valley speculates may contain a potential three trillion cubic feet of natural gas in place in all five zones. Downhole data from the zones show 40% porosity with 70% gas saturation at an average 3.5 ohms for about 80 billion cubic feet per 160 acres.

Tri-Valley notes that since it assembled the project in 2001, the price of natural gas has climbed steadily from the $1.80 range to the present spot price of more than $9.00 per thousand cubic feet. The Company believes its foresight in acquiring the 13 square miles of lands to put the play together will provide a considerable extra bonus for all its shareholders and drilling partners once commercial rates are achieved.

The Sunrise Natural Gas Project is one of 26 very large, high-impact targets in Tri-Valley's TVOG Opus I Drilling Program L.P. The program is designed to mitigate exploration risk, provide opportunity for exceptional upside return and maximize long-standing tax benefits for investors.

Tri-Valley, along with most of its prospect inventory, is located in Bakersfield, California, a region which produces three times as much oil per day as the entire state of Oklahoma. The Company believes that huge exploration targets remain in this prolific producing area and has leased approximately 65,000 acres covering some of its largest prospects.

Tri-Valley Corporation is a full reporting company publicly traded over the counter in the U.S. under the symbol TRIL.OB. It is also listed for trading on the Berlin Stock Exchange under the symbol TVC WKN 911919.

This press release contains forward-looking statements that involve risks and uncertainties. Actual results, events and performance could vary materially from those contemplated by these forward-looking statements which includes such words and phrases as exploratory, wildcat, prospect, speculates, unproved, prospective, very large, expect, potential, etc. Among the factors that could cause actual results, events and performance to differ materially are risks and uncertainties discussed in the company's quarterly report on Form 10-Q for the quarter ended September 30, 2002, and the annual report on Form 10-K for the year ended December 31, 2001.