Oregon Steel Mills, Inc. announced the pricing of its public offering of 7,500,000 shares of common stock at a price to the public of $16.00 per share. All shares are being offered by the company.

The underwriters have been granted an option to purchase up to an additional 1,125,000 shares from Oregon Steel Mills, Inc. to cover over-allotments, if any. The offering is subject to customary closing conditions and is expected to close on Tuesday, October 5, 2004.

CIBC World Markets Corp. and UBS Securities LLC serve as joint book running managers of the offering. Jefferies & Co., Inc., KeyBanc Capital Markets and D.A. Davidson & Co. are acting as co-managers. Copies of the prospectus relating to the offering may be obtained from either CIBC World Markets Corp.

A registration statement relating to these securities was filed with and has been declared effective by the U.S. Securities and Exchange Commission.

Oregon Steel cautions that this announcement does not constitute an offer to sell or the solicitation of an offer to buy any of the securities, and that there shall not be any sale of the securities in any state or jurisdiction in which such an offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state or jurisdiction.

Oregon Steel Mills, Inc. is organized into two divisions. The Oregon Steel Division produces steel plate, coil, welded pipe and structural tubing from plants located in Portland, Ore.; Napa, Calif.; and Camrose, Alta., Canada. The Rocky Mountain Steel Mills Division, located in Pueblo, Colo., produces steel rail, rod, bar, and tubular products.