Exhibit 99.1

NEWS

RELEASE

2009-05

FOR IMMEDIATE RELEASE

Contact: Kristine Boyd

713-688-9600 x135

FRONTIER OIL DECLARES CASH DIVIDEND

HOUSTON, TEXAS, April 30, 2009 – The Board of Directors of Frontier Oil Corporation (NYSE: FTO) declared a regular quarterly cash dividend on the Company’s common stock of $0.06 per share ($0.24 annualized).  The dividend is payable on July 16, 2009 to shareholders of record as of the close of business on June 26, 2009.

Frontier operates a 130,000 barrel-per-day refinery located in El Dorado, Kansas, and a 52,000 barrel-per-day refinery located in Cheyenne, Wyoming, and markets its refined products principally along the eastern slope of the Rocky Mountains and in other neighboring plains states.  Information about the Company may be found on its web site www.frontieroil.com.

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