Oregon Steel Mills Announces Marketing Agreement with Maverick Tube

Oregon Steel Mills, Inc. (NYSE:OS) announced today a
marketing agreement with Maverick Tube Corporation. The agreement
supersedes any previously announced agreements and follows the
successful start-up, in December of 2005, at Oregon Steel's Rocky
Mountain Steel Mills' ("RMSM") seamless pipe mill in Pueblo, Colorado
(the "Mill"). The agreement provides for Maverick Tube to be the
exclusive worldwide marketing and sales representative for RMSM
seamless pipe products. This agreement is for a minimum of 48,000 tons
per year and commences immediately. The Mill has production
capabilities of approximately 150,000 tons annually, depending on
product mix, and is expected to produce at an annual rate of 100,000
tons with an emphasis on quench and temper seamless casing products.
The seamless pipe produced by the Mill serves various markets but, in
particular, the energy markets in the recovery of natural gas and oil.
   Jim Declusin, Oregon Steel Mills' President and CEO, stated, "We
are excited about this alliance as it enables us, through an
established industry participant, to position our seamless products in
the oil country tubular goods markets immediately. We anticipate
continued high demand for all of our energy-related products and,
assuming that selling prices remain favorable, we expect the energy
part of our business to record strong financial performance into the
foreseeable future."
   Rob Simon, Vice-President and General Manager of RMSM, added, "We
are pleased about the reopening of our seamless mill and the
successful start-up we experienced in December of 2005. With the
investment we are making in this facility, we continue to expand our
offerings of value-added products. This agreement with Maverick Tube
allows us to combine our process and manufacturing expertise with the
sales and marketing skills of Maverick to bring our product to
market."

   FORWARD-LOOKING STATEMENTS

   Forward-looking statements in this release are made pursuant to
the safe harbor provisions of the Private Securities Litigation Reform
Act of 1995. Such forward-looking statements are subject to risks and
uncertainties and actual results could differ materially from those
projected. Such risks and uncertainties include, but are not limited
to, general business and economic conditions; competitive products and
pricing, as well as fluctuations in demand; cost and availability of
raw materials; potential equipment malfunction, and plant construction
and repair delays. For more detailed information, please review the
discussion of risks, which may cause results to differ materially, in
the Company's most recently filed Form 10-K, Form 10-Q and other SEC
reports.
   These forward-looking statements should not be relied upon as
representing the Company's views as of any subsequent date and the
Company undertakes no obligation to update or revise the
forward-looking statements, whether as a result of new information,
future events or otherwise, after the date they are made.

   Oregon Steel Mills, Inc. is organized into two divisions. The
Oregon Steel Division produces steel plate, coil, small- and
large-diameter line pipe, casing and structural tubing from plants
located in Portland, Oregon, and Camrose, Alberta, Canada. The Rocky
Mountain Steel Mills Division, located in Pueblo, Colorado, produces
steel rail, rod and bar, and seamless tubular products.