Exhibit 99.1


                              FOR IMMEDIATE RELEASE


         HOLLY CORPORATION DELIVERS NOTICE OF MATERIAL ADVERSE EFFECT TO
                 FRONTIER OIL IN CONNECTION WITH PENDING MERGER

Dallas, TX, August 21, 2003 - Holly Corporation (AMEX: HOC) today announced that
pursuant to its Merger Agreement with Frontier Oil Corporation (NYSE: FTO),
Holly has formally notified Frontier of Holly's position that the circumstances
described below constitute a breach of Frontier's representations and warranties
in the Merger Agreement as to the absence of litigation or other circumstances
which could reasonably be expected to have a material adverse effect on
Frontier. Under the Merger Agreement, if a breach has occurred and is not timely
cured, Holly is not obligated to close the merger and has the right to terminate
the Merger Agreement. At this time, Holly's Board has not taken any action to
terminate the Merger Agreement under this or any other provision, nor has the
Holly Board changed its recommendation with respect to the merger.

Holly believes that recently filed toxic tort lawsuits against Frontier and
several other defendants in California state court on behalf of over 400
plaintiffs, mostly former Beverly Hills High School students, and related
contingent and other obligations and liabilities of Frontier, raise substantial
risks and uncertainties that could reasonably be expected to materially
adversely affect the condition and prospects of Frontier.

After extensively reviewing the information available to Holly regarding these
lawsuits, claims and obligations, and consulting with counsel, Holly believes
that:

     o   the Beverly Hills lawsuits have the potential to be prolonged
         distractions since it could be four to five years before the expected
         trial for the first small group of plaintiffs; a successful result for
         the defendants in the first trial would not necessarily prevent future
         trials by other plaintiffs;

     o   these lawsuits will involve substantial defense costs; the costs to
         defend the plaintiffs' claims against Frontier alone could easily
         involve tens of millions of dollars through the anticipated completion
         of the trial for the first small group of plaintiffs;

     o   these lawsuits have not been brought as class actions and it would be
         very unlikely that any substantial number of claims could be settled
         for inconsequential amounts, especially in the early years; and

     o   these lawsuits present the risk of very substantial adverse judgments
         against Frontier, which could involve hundreds of millions of dollars
         in potential exposure to Frontier.

Holly believes the lawsuit precipitously launched yesterday by Frontier distorts
the background and reasons for Holly's concerns about the pending merger. Before
entering into the Merger Agreement, Frontier advised Holly that the Beverly
Hills situation was not then, and would not later become, a material problem and
also expressly represented the same to Holly in the Merger Agreement. Frontier



also agreed during the final negotiations and in the terms of the final Merger
Agreement that Holly would be able to continue to review and consider subsequent
developments in the Beverly Hills situation and its future impact on Frontier up
until the closing of the merger. Since the signing of the Merger Agreement, the
Beverly Hills' risks have become substantially worse to the point where Frontier
is now a defendant in lawsuits with over 400 plaintiffs represented by
nationally prominent plaintiffs' firms. Holly also anticipates that additional
lawsuits involving substantial numbers of plaintiffs will probably be brought by
these law firms, as well as by another major plaintiffs' law firm representing
additional plaintiffs that have already filed notices of claims to be brought.

After repeated discussions with Frontier regarding Holly's growing concerns
about the Beverly Hills situation, Holly and Frontier in recent weeks considered
various alternatives in seeking a revised transaction that would better protect
Holly's stockholders from the additional risks and uncertainties Holly believes
have become part of an investment in Frontier stock.

The company noted:

"Holly believes that the allegation in the Frontier lawsuit that Holly only
recently disclosed its concerns to Frontier about the Beverly Hills situation to
preserve the possible enhancement in the value of Holly's pipeline operations is
false. This allegation is a smokescreen to cloud the real Frontier issue -- the
substantial risks and uncertainties now inherent in Frontier's stock as a result
of the lawsuit quagmire that the Beverly Hills situation has become. This is not
about Holly retaining the upside in our pipeline assets for Holly stockholders -
it is about Frontier attempting to spread its downside litigation risks to Holly
stockholders."

Holly, headquartered in Dallas, Texas, operates through its subsidiaries a
60,000 bpd refinery located in Artesia, New Mexico that is being expanded to
75,000 bpd, a 25,000 bpd refinery in Woods Cross, Utah, and a 7,500 bpd refinery
in Great Falls, Montana. Holly also owns, leases and/or operates approximately
2,000 miles of crude oil and refined product pipelines in the west Texas and New
Mexico region and refined product terminals in several states.

The following is a "safe harbor" statement under the Private Securities
Litigation Reform Act of 1995: The statements in this press release relating to
matters that are not historical facts are forward-looking statements based on
management's belief and assumptions using currently available information and
expectations as of the date hereof, are not guarantees of future performance and
involve certain risks and uncertainties. Although the company believes that the
expectations reflected in such forward-looking statements are reasonable, the
company cannot give any assurances that these expectations will prove to be
correct. Therefore, actual outcomes and results could materially differ from
what is expressed, implied or forecast in such statements. Such differences
could be caused by a number of factors including, but not limited to, risks and
uncertainties with respect to the actions of actual or potential competitive
suppliers of refined petroleum products in the company's markets, the demand for
and supply of crude oil and refined products, the spread between market prices
for refined products and market prices for crude oil, the possibility of
constraints on the transportation of refined products, the possibility of
inefficiencies or shutdowns in refinery operations or pipelines, effects of
governmental regulations and policies, the availability and cost of financing to
the company, the effectiveness of the company's capital investments and
marketing strategies, the company's efficiency in carrying out construction
projects, the successful integration of the Woods Cross refinery, the outcome
with respect to the proposed transaction with Frontier, the possibility of
terrorist attacks and the consequences of any such attacks, general economic
conditions, and other financial, operational and legal risks and uncertainties
detailed from time to time in the company's Securities and Exchange Commission
filings. The company assumes no duty to publicly update or revise such
statements, whether as a result of new information, future events or otherwise.



FOR FURTHER INFORMATION, Contact:

Stephen J. McDonnell, Vice President and Chief Financial Officer
Holly Corporation
214/871-3555