UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                               WASHINGTON DC 20549

                                    FORM 8-K
                                 CURRENT REPORT
                       PURSUANT TO SECTION 13 OR 15(D) OF
                       THE SECURITIES EXCHANGE ACT OF 1934
         DATE OF REPORT (DATE OF EARLIEST EVENT REPORTED): MAY 27, 2004

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

      DELAWARE                       1-9887                 94-0506370
--------------------------------------------------------------------------------
(State or other jurisdiction      (Commission              (IRS Employer
 of incorporation)                 File Number)             Identification No.)


1000 S.W. BROADWAY, SUITE 2200; PORTLAND, OREGON                97205
--------------------------------------------------------------------------------
(Address of principal executive offices)                      (Zip code)


                                 (503) 223-9228
--------------------------------------------------------------------------------
              (Registrant's telephone number, including area code)


<PAGE>


ITEM 7.  FINANCIAL STATEMENTS AND EXHIBITS.

(c)  Exhibits

EXHIBIT
NUMBER            DESCRIPTION

99.1     Oregon Steel Mills,  Inc.  Company  Press Release dated May 27, 2004,
         updating the financial  outlook for the second  quarter ending June 30,
         2004.

ITEM 9. REGULATION FD DISCLOSURE

On May 27, 2004, the Company issued a press release updating the financial
outlook for the second quarter ending June 30, 2004. A copy of the press release
is filed as Exhibit 99.1 to this report and is incorporated herein by reference.


                                   SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.

                            OREGON STEEL MILLS, INC.
--------------------------------------------------------------------------------
                                  (Registrant)



Date:  May 27,2004               By:       /s/ Jeff S. Stewart
       ---------------              -----------------------------------------
                                          Jeff S. Stewart
                                          Corporate Controller
                                          (Principal Accounting Officer)
[{"type": "8-K", "sequence": "1", "filename": "osm8kpress527.txt", "description": "OSM 8-K FOR PRESS RELEASE", "secsgml_size_bytes": 2635}]
{"company-data": {"conformed-name": "OREGON STEEL MILLS INC", "cik": "0000830260", "assigned-sic": "3312", "irs-number": "940506370", "state-of-incorporation": "DE", "fiscal-year-end": "1231"}, "filing-values": {"form-type": "8-K", "act": "34", "file-number": "001-09887", "film-number": "04833523"}, "business-address": {"street1": "1000 SW BROADWAY", "street2": "STE 2200", "city": "PORTLAND", "state": "OR", "zip": "97205", "phone": "5032405788"}, "mail-address": {"street1": "PO BOX 5368", "city": "PORTLAND", "state": "OR", "zip": "97228"}}
UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                               WASHINGTON DC 20549

                                    FORM 8-K
                                 CURRENT REPORT
                       PURSUANT TO SECTION 13 OR 15(D) OF
                       THE SECURITIES EXCHANGE ACT OF 1934
         DATE OF REPORT (DATE OF EARLIEST EVENT REPORTED): MAY 27, 2004

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

      DELAWARE                       1-9887                 94-0506370
--------------------------------------------------------------------------------
(State or other jurisdiction      (Commission              (IRS Employer
 of incorporation)                 File Number)             Identification No.)

1000 S.W. BROADWAY, SUITE 2200; PORTLAND, OREGON                97205
--------------------------------------------------------------------------------
(Address of principal executive offices)                      (Zip code)

                                 (503) 223-9228
--------------------------------------------------------------------------------
              (Registrant's telephone number, including area code)
ITEM 7.  FINANCIAL STATEMENTS AND EXHIBITS.

(c)  Exhibits

EXHIBIT
NUMBER            DESCRIPTION

99.1     Oregon Steel Mills,  Inc.  Company  Press Release dated May 27, 2004,
         updating the financial  outlook for the second  quarter ending June 30,
         2004.

ITEM 9. REGULATION FD DISCLOSURE

On May 27, 2004, the Company issued a press release updating the financial
outlook for the second quarter ending June 30, 2004. A copy of the press release
is filed as Exhibit 99.1 to this report and is incorporated herein by reference.

                                   SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.

                            OREGON STEEL MILLS, INC.
--------------------------------------------------------------------------------
                                  (Registrant)

Date:  May 27,2004               By:       /s/ Jeff S. Stewart
       ---------------              -----------------------------------------
                                          Jeff S. Stewart
                                          Corporate Controller
                                          (Principal Accounting Officer)