Tri-Valley Corporation Completes Expanded Phase 1 Claflin Drilling Program

Tri-Valley Corporation (NYSE Amex: TIV) today announced that it has
completed an expanded Phase 1 development drilling program at its
Claflin oil project, located in the Edison Oil Field near Bakersfield,
California. The Company has drilled eight new wells, up from the six
wells initially planned. These new wells are part of Tri-Valley′s
overall plan to drill a total of 22 new wells at Claflin during 2011 to
convert 2.1 million barrels of net proved undeveloped oil reserves
('PUDs?) on the property to proved developed and producing ('PDP?)
status and to increase oil production. The net proved undeveloped
reserves were included in the reserves disclosed in the Company′s Annual
Report on Form 10-K for the year ended December 31, 2010, and filed with
the U.S. Securities and Exchange Commission on March 22, 2011.

Tri-Valley is currently completing the installation of well-site
production equipment and tie-in of the new wells to existing production
facilities at Claflin. The Company expects to commence an initial steam
injection cycle on the first well in early May and that the new wells
will have received an initial steam injection cycle by the end of July;
however, new steam generating capacity being installed at Claflin could
accelerate completion of this initial steam injection work on the new
wells. First oil production is anticipated from some of the new wells by
June. Following first production from these new wells, there will be a
90-day evaluation period during which Tri-Valley will analyze the
performance of the new wells prior to commencement of the second phase
of the Claflin development to complete the remaining 14 new wells by the
end of the year.

'We are ahead of schedule on our plans to develop the Claflin property
to drive increased oil production in 2011,? said Maston N. Cunningham,
President and CEO of Tri-Valley Corporation. 'Our plan calls for a total
of 13 new vertical wells and nine new horizontal wells to be drilled on
the property this year. If we are successful, we expect to exit 2011
with gross daily production of about 800 barrels of oil from the
property.?

'With the closing of our recent private placement financing, we raised
nearly five million dollars in new capital that will allow us to pursue
our development plans at Claflin,? continued Mr. Cunningham. 'We would
like to welcome Ironman Energy Master Fund, an experienced oil and gas
investment fund and major participant in our recent financing, as a
significant new shareholder of Tri-Valley Corporation.?

'Negotiations with adjacent land and mineral owners to secure permits
for the 3-D seismic acquisition area for the Claflin and adjoining Brea
properties have taken more time than originally planned, but we believe
that seismic acquisition work should start by the end of May,? added Mr.
Cunningham. 'This new 3-D data will useful for our exploitation plans
for Claflin and Brea, including better geologic control during
horizontal drilling operations later this year in the second phase of
Claflin development.?

About Tri-Valley

Tri-Valley Corporation explores for and produces oil and natural gas in
California and has two exploration-stage gold properties in Alaska.
Tri-Valley is incorporated in Delaware and is publicly traded on the
NYSE Amex exchange under the symbol 'TIV.' Our Company website, which
includes all SEC filings, is www.tri-valleycorp.com.

Forward-Looking Statements

All statements contained in this press release that refer to future
events or other non-historical matters are forward-looking statements.
By way of example, statements contained in this press release related to
the expected timeline for well-drilling completion, first oil
production, installation of facility upgrades and seismic study results,
as well as the anticipated number of wells to be drilled, gross barrel
production and production rates, and such other future events, business
plans and objectives of management for future operations, are
forward-looking statements. Although the Company does not make
forward-looking statements unless it believes it has a reasonable basis
for doing so, the Company cannot guarantee their accuracy. These
statements are only predictions based on management′s expectations as of
the date of this press release, and involve known and unknown risks,
uncertainties and other factors, including: the Company′s ability to
obtain additional funding; imprecise estimates of oil reserves; drilling
hazards such as equipment failures, fires, explosions, blow-outs, and
pipe failure; shortages or delays in the delivery of drilling rigs and
other equipment; problems in delivery to market; adverse weather
conditions; compliance with governmental and regulatory requirements;
fluctuations in oil prices; and such other risks and factors that are
discussed in the Company′s filings with the Securities and Exchange
Commission from time to time, including under 'Item 1A. Risk Factors?
and 'Item 7. Management′s Discussion and Analysis of Financial Condition
and Results of Operations,? contained in the Company′s Annual Report on
Form 10-K for the year ended December 31, 2010. Except as required by
law, the Company undertakes no obligation to update or revise publicly
any of the forward-looking statements after the date of this press
release to conform such statements to actual results or to reflect
events or circumstances occurring after the date of this press release.

Company Contacts:

John Durbin, 661-864-0500

jdurbin@tri-valleycorp.com

or

Investor
Contacts:

EVC Group, Inc.

Doug Sherk/Jenifer Kirtland,
415-896-6820

dsherk@evcgroup.com

jkirtland@evcgroup.com

or

Media
Contact:

EVC Group, Inc.

Chris Gale, 646-201-5431

cgale@evcgroup.com