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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,
 GN+NcOoIwgcbMo7TBCHGh4iVx1cVnVe0QErDAr+s1isYzXnhneG5A+oo/RiugHoM
 ph+Z63ItkYQpsTuR8FN52w==

<SEC-DOCUMENT>0001179110-04-018380.txt : 20040920
<SEC-HEADER>0001179110-04-018380.hdr.sgml : 20040920
<ACCEPTANCE-DATETIME>20040920183557
ACCESSION NUMBER:		0001179110-04-018380
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040917
FILED AS OF DATE:		20040920
DATE AS OF CHANGE:		20040920

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			DEA PETER A
		CENTRAL INDEX KEY:			0001132295
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-10389
		FILM NUMBER:		041038214

	BUSINESS ADDRESS:	
		STREET 1:		1515 ARAPAHOE STREET
		STREET 2:		TOWER 3 SUITE 1000
		CITY:			DENVER
		STATE:			CO
		ZIP:			80202
		BUSINESS PHONE:		303-606-4072

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			WESTERN GAS RESOURCES INC
		CENTRAL INDEX KEY:			0000856716
		STANDARD INDUSTRIAL CLASSIFICATION:	NATURAL GAS DISTRIBUTION [4924]
		IRS NUMBER:				841127613
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1099 18TH STREET, SUITE 1200
		CITY:			DENVER
		STATE:			CO
		ZIP:			80202-1955
		BUSINESS PHONE:		303 452 5603

	MAIL ADDRESS:	
		STREET 1:		1099 18TH STREET, SUITE 1200
		CITY:			DENVER
		STATE:			CO
		ZIP:			80202-1955
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-09-17</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000856716</issuerCik>
        <issuerName>WESTERN GAS RESOURCES INC</issuerName>
        <issuerTradingSymbol>WGR</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001132295</rptOwnerCik>
            <rptOwnerName>DEA PETER A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/- WESTERN GAS RESOURCES, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>1099 18TH STREET, SUITE 1200</rptOwnerStreet2>
            <rptOwnerCity>DENVER</rptOwnerCity>
            <rptOwnerState>CO</rptOwnerState>
            <rptOwnerZipCode>80202</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CEO &amp; President</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>28.35</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-09-17</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>84000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2005-09-17</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2010-09-17</value>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>84000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>84000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Options are exercisable in 1/3 annual increments, commencing on the first anniversary of the grant date and terminate on the earlier of (i) five (5) years from the vesting date, or (ii) ten (10) years after the grant date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Peter A. Dea</signatureName>
        <signatureDate>2004-09-20</signatureDate>
    </ownerSignature>
</ownershipDocument>

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