..                       SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

                                    FORM 10-K/A
                                (Amendment No. 1)

               ANNUAL REPORT FILED PURSUANT TO SECTION 13 OR 15(D)
                     OF THE SECURITIES EXCHANGE ACT OF 1934

FOR THE FISCAL YEAR ENDED DECEMBER 31, 2001        COMMISSION FILE NUMBER 1-9887

                            OREGON STEEL MILLS, INC.
             (Exact name of registrant as specified in its charter)

              DELAWARE                                      94-0506370
-------------------------------------------------------------------------------
      (State or other jurisdiction of                      (IRS Employer
       incorporation or organization)                    Identification No.)

             1000 S.W. BROADWAY
                 SUITE 2200
               PORTLAND, OREGON                               97205
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     (Address of principal executive office)                (Zip Code)


        REGISTRANT'S TELEPHONE NUMBER, INCLUDING AREA CODE: (503) 223-9228

              SECURITIES REGISTERED PURSUANT TO SECTION 12(B) OF THE ACT:

                                                 Name of each exchange
          Title of each class                     on which registered
        ------------------------               --------------------------------

 Common Stock, $.01 par value per share           New York Stock Exchange
 11% First Mortgage Notes due 2003                New York Stock Exchange

           SECURITIES REGISTERED PURSUANT TO SECTION 12(G) OF THE ACT:

                                      None

     Indicate by check mark if disclosure of delinquent filers pursuant to Item
405 of Regulation S-K is not contained herein and will not be contained,  to the
best of registrant's knowledge, in definitive proxy or information statements
incorporated by reference in Part III of this Form 10-K or any amendment to this
Form 10-K.[ X]

      Indicate by check mark whether the registrant (1) has filed all reports
required to be filed by Section 13 or 15(d) of the Securities Exchange Act of
1934 during the preceding 12 months (or for such shorter period that the
registrant was required to file such reports) and (2) has been subject to such
filing requirements for the past 90 days.

                                                  Yes  X       No
                                                      ---         ---

      State the aggregate market value of the voting stock held by
non-affiliates of the registrant.

               BASED ON LAST SALE, JANUARY 31, 2002: $148,246,310

      Indicate the number of shares outstanding of each of the registrant's
classes of stock as of January 31, 2002:

      COMMON STOCK, $.01 PAR VALUE                         25,786,854
      ----------------------------                 -----------------------------
            (Title of Class)                      (Number of shares outstanding)

                      DOCUMENTS INCORPORATED BY REFERENCE:

      Proxy statement for the Registrant's Annual Meeting of Stockholders to be
held April 25, 2002 is incorporated by reference into Part III of this report.



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                            OREGON STEEL MILLS, INC.
                                TABLE OF CONTENTS


   Attached are the following exhibits:

10.11**  Annual Incentive Plan

21.0     Subsidiaries of Registrant

23.0     Consent of Independent Accountants

**Management contract or compensatory plan.




                        SIGNATURES REQUIRED FOR FORM 10-K/A

         Pursuant to the requirements of Section 13 or 15(d) of the Securities
Exchange Act of 1934, Oregon Steel Mills, Inc. has duly caused this amendment
to be signed on its behalf by the undersigned, thereunto duly authorized.

                                                OREGON STEEL MILLS, INC.
                                                (Registrant)

                                                By    /s/ L. Ray Adams
                                                ---------------------------
                                                Vice President - Finance,
                                                Chief Financial Officer,
                                                and Treasurer
                                                (Principal Financial Officer)