Tri-Valley Drilling Oil Creek Play.

Energy Editors/Business Editors

BAKERSFIELD, Calif.--(BUSINESS WIRE)--Sept. 2, 2003

Tri-Valley Corporation (OTCBB:TRIL) announced today that the exploration well on its big Oil Creek Prospect has been spudded, drilled to 2,300 feet and surface pipe set in preparation to continue drilling to the target depth of 10,800 feet.

The Oil Creek Prospect is located near Coalinga, California and is surrounded by enormous fields which have so far produced nearly two billion barrels of oil and nearly four trillion cubic feet of natural gas. Still, the prospect is about a mile and a half from existing production and has somewhat of a "wildcat" status looking for a new field discovery.

"With the wellbore passing through at least six separate zones that produce in the area, we believe we've considerably increased the chance for discovery success. And, if we are lucky enough to have all six zones productive, it could be a bases loaded home run company maker for Tri-Valley," said F. Lynn Blystone, president and chief executive officer.

To illustrate, Blystone noted that the Tri-Valley exploration staff postulates a potential in the range of 150 million barrels of oil equivalent from the aggregate mapped zones and the Company has a 25% carried working interest in the initial test well so that even partial success could yield a multiple return to its drilling partners and the shareholders of Tri-Valley Corporation.

"Oil Creek, with its multiple zones of stacked pay and exceptionally large upside potential, is typical of the big targets we are generating for the exploration opportunity for our partners and shareholders. We have designed statistical probability of discovery success on a very large scale which can also help consumers," Blystone said.

Given the declining California production against rising demand in the State, he believes the Oil Creek Prospect will be closely watched by the industry as well as investors who can benefit from a major west coast discovery.

"We operate in the end of the business that can have dry holes and exploration failure. But when everyone knows you are swinging for the fence and could hit the home run, they will be watching in case they need to jump into the area if we have success," he said.

The Company and its subsidiaries are headquartered in Bakersfield, California, a premier oil-producing province of the western hemisphere. Tri-Valley Corporation stock is publicly traded on the over-the-counter bulletin board under the symbol "TRIL.OB" in the United States and in Europe on the Berlin and Frankfurt Stock Exchanges under the symbol "TVC WKN 911919." Our company websites, which include all SEC filings, are www.tri-valleycorp.com and www.tri-valley.de.

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 June 30, 2003, and the annual report on Form 10-K for the year ended December 31, 2002.