Completion and Production Testing to Begin Immediately at Tri-Valley's Ekho No. 1.

Business Editors

BAKERSFIELD, Calif.--(BUSINESS WIRE)--May 11, 2000

Logging and interpretation of the Ekho No. 1 has been completed and, as a result of all core and log data, a decision has been made to proceed with completion and production testing, it was announced today by F. Lynn Blystone, Tri-Valley Oil & Gas Co.'s chief executive officer.

The primary target, the Vedder Sands, has a gross sand thickness of 440 feet. The Phacoides, a secondary target, has a gross sand thickness of 160 feet over two intervals. As originally projected, other horizons that have indications of hydrocarbons include the Olcese and Antelope/MacDonald intervals. The Olcese has a gross sand thickness of 965 feet, the Antelope/MacDonald interval, a producing horizon on the Lost Hills structure, has a thickness of 975 feet in EKHO No. 1. Based upon the log interpretation there is potential for hydrocarbons in all the sand.

Casing will be run into the top of the Vedder Sands and the Vedder and Phacoides section will then be openhole production tested from the top of the Vedder to T.D. at 19,085 feet. Completion and production testing of the Vedder and Phacoides in the EKHO No. 1 is anticipated to take 60 days.

As reported in an article by James Flanigan in the May 7, 2000, edition of the L.A. Times, there is enormous potential for deep oil and gas reserves in the San Joaquin Valley. This forms the basis of the huge Ekho Project put together by TVOG as operator with nine Canadian junior companies and several individual investors. TVOG drilled the Ekho No. 1, located approximately 45 miles northwest of Bakersfield, California, in record time, taking only 80 drilling days to reach 19,085 feet.

The nine Canadian Venture Exchange (CDNX) resource companies and their various initial interests are: Aster Ventures Corp (ASV.V) 20%; Curion Ventures Corp. (CUV.V) 20%; Lucre Ventures Ltd. (LVD.V) 12%; Berkshire International Mining Ltd. (BKR.V) 10%; CVL Resources (CVL.V) 9.64%; Consolidated Bradbury International Equities (CBN.V) 5%; Curlew Lake Resources (CWQ.V) 5%; Pan Ocean Explorations (POE.V) 5%; and Prairie Pacific Energy Corporation (PRP.V) 5%.

Tri-Valley Corporation is the publicly traded parent (OTCBB:TRIL) of Tri-Valley Oil & Gas Company, which will own 12.5% of the well after completion and back in for an additional 12.5% interest after payout of the well. More information is available at Tri-Valley's Web site, www.tri-valleycorp.com.

This news 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. 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-QSB for the quarter ended September 30, 1999, and the annual report on Form 10-KSB for the year ended December 31, 1999.