-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 DK8lFGKvSvQBXcNNDEE9TPt5m+KWY8e2rZphQ2gQp8C4EzIwTEuS9BwSfsYdlB+K
 p3Y0sKEehGAlsK7/8h+0yA==

<SEC-DOCUMENT>0000830260-03-000027.txt : 20031218
<SEC-HEADER>0000830260-03-000027.hdr.sgml : 20031218
<ACCEPTANCE-DATETIME>20031218190226
ACCESSION NUMBER:		0000830260-03-000027
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20031208
FILED AS OF DATE:		20031218

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DIDYK STEPHEN H
		CENTRAL INDEX KEY:			0001184521

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-09887
		FILM NUMBER:		031063413

	BUSINESS ADDRESS:	
		STREET 1:		1000 SW BROADWAY
		STREET 2:		SUITE 2200
		CITY:			PORTLAND
		STATE:			OR
		ZIP:			98683

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			OREGON STEEL MILLS INC
		CENTRAL INDEX KEY:			0000830260
		STANDARD INDUSTRIAL CLASSIFICATION:	STEEL WORKS, BLAST FURNACES  ROLLING MILLS (COKE OVENS) [3312]
		IRS NUMBER:				940506370
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1000 SW BROADWAY
		STREET 2:		STE 2200
		CITY:			PORTLAND
		STATE:			OR
		ZIP:			97205
		BUSINESS PHONE:		5032405788

	MAIL ADDRESS:	
		STREET 1:		PO BOX 5368
		CITY:			PORTLAND
		STATE:			OR
		ZIP:			97228
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>osmdf403_ex.xml
<TEXT>
<XML>
<?xml version="1.0"?>
<!-- - EDGAR Ease Plus 1.0                                   07/25/03  TT    -->
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>
   <periodOfReport>2003-12-08</periodOfReport>
   <notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000830260</issuerCik>
        <issuerName>OREGON STEEL MILLS INC</issuerName>
        <issuerTradingSymbol>OS</issuerTradingSymbol>
   </issuer>
   <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001184521</rptOwnerCik>
            <rptOwnerName>DIDYK STEPHEN H</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1></rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity></rptOwnerCity>
            <rptOwnerState></rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
         <isDirector>0</isDirector>
         <isOfficer>0</isOfficer>
         <isTenPercentOwner>0</isTenPercentOwner>
         <isOther>1</isOther>
         <otherText>Director, Rail and Semi-finish</otherText>
      </reportingOwnerRelationship>
   </reportingOwner>
 <nonDerivativeTable>
   <nonDerivativeTransaction>
      <securityTitle>
         <value>COMMON STOCK</value>
      </securityTitle>
      <transactionDate>
         <value>2003-12-08</value>
      </transactionDate>
      <deemedExecutionDate>
         <value>2003-12-16</value>
      </deemedExecutionDate>
      <transactionCoding>
         <transactionFormType>4</transactionFormType>
         <transactionCode>S</transactionCode>
         <equitySwapInvolved>0</equitySwapInvolved>
      </transactionCoding>
      <transactionAmounts>
         <transactionShares>
           <value>1500</value>
         </transactionShares>
         <transactionPricePerShare>
           <value>3.40</value>
         </transactionPricePerShare>
         <transactionAcquiredDisposedCode>
           <value>D</value>
         </transactionAcquiredDisposedCode>
      </transactionAmounts>
      <postTransactionAmounts>
         <sharesOwnedFollowingTransaction>
           <value>4500</value>
         </sharesOwnedFollowingTransaction>
      </postTransactionAmounts>
      <ownershipNature>
         <directOrIndirectOwnership>
            <value>D</value>
         </directOrIndirectOwnership>
      </ownershipNature>
   </nonDerivativeTransaction>
 </nonDerivativeTable>
   <ownerSignature>
      <signatureName>Jeff S. Stewart</signatureName>
      <signatureDate>2003-12-18</signatureDate>
   </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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