Tri-Valley Rigs Up to Drill Big Oil and Gas Play.

Energy Editors/Business Editors

BAKERSFIELD, Calif.--(BUSINESS WIRE)--Aug. 19, 2003

Tri-Valley Corporation (OTCBB:TRIL) expects a big boost from its oil and natural gas exploration efforts as it builds location on its big Oil Creek Prospect near Coalinga, California, to move in a drill rig next week.

The Company expects the test to be closely watched by the industry as the 10,800-foot bore will pass through at least six separate potentially oil- and gas-rich horizons that are near to the giant Coalinga Field, with area production nearly two billion barrels of oil and nearly four trillion cubic feet of natural gas.

"This very large target is typical of our exploration inventory where we strive for discovery success on a large scale that can exceptionally reward our drilling partners and add exponential value to our shares. It can also make a meaningful contribution to consumer supply needs," said F. Lynn Blystone, president and chief executive officer.

Company officials noted that dry hole risk exists at every level and prospect size in the exploration business, but that success on very big targets like Oil Creek can add extraordinary value quickly. In the case of the Oil Creek Prospect, Tri-Valley geologists, engineers and geophysicists have speculated a potential, if all six horizons are hydrocarbon-saturated, in the range of 125 million barrels of oil and 125 billion cubic feet of natural gas, all unproven at this stage. Statistically, the best place to look for a major oilfield is within 12 miles of an existing major field, and the Oil Creek Prospect is one and a half miles southwest of the East Coalinga Oilfield Extension.

"The supporting data from many sources along with its proximity to giant producing areas are compelling reasons to take the $3.5 million financial risk to drill the Oil Creek play. Our partners are all individuals who wish to access the emerging investment opportunity related to the growing supply/demand imbalance, particularly in natural gas. We have designed an excellent program to leverage such investment in a big way right here and substantially mitigate the risk in the Bakersfield area, a region that produces three times as much oil per day as the entire state of Oklahoma," Blystone said.

Blystone noted that Tri-Valley's most recent prospect drill, the Sunrise-Mayel No. 2HR gas well near Delano, California, is still cleaning up after hydraulic fracturing, and the Company will pump out the remaining fluid over the next two weeks in order to establish a flow rate.

"Again, this is a real nail-biter, as a commercial flow rate on the Sunrise well will infer gross prospect viability and justify not only building a pipeline to sell that production from this well, but also develop more than 10 square miles of mapped area in the play, which we believe holds a massive amount of gas in place that could make a difference in California's `gas pains,'" Blystone said.

Both the Sunrise-Mayel No. 2HR and the Oil Creek Prospect are part of a larger inventory of 26 very large targets assembled by Tri-Valley for a major exploration push to find big, new, flush production, long-life oil and gas reserves despite the probability of numerous dry holes in the process. The Company believes that it can deliver a multiple return to investors on only 1% discovery success of the aggregate potential of the 26 prospects because the selected targets are so large.

"In our country, the responsibility for replacing the reserves of the nation is left to the private sector. We have been able to assemble major company-sized targets and craft a drilling fund that enables individual, accredited investors who can accept the risks to participate. Discovery success is a win, win, win for drilling partners, Tri-Valley shareholders, and American citizens," Blystone 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" 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 include 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.