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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,
 WsclagtwbokaD4PYFgwqpuaBVNSes14t2POYjwi43ynyqArR9SmJkx7k/ye61MU8
 uST3bwryyOABdCe0UN86Eg==

<SEC-DOCUMENT>0001209191-05-065249.txt : 20051222
<SEC-HEADER>0001209191-05-065249.hdr.sgml : 20051222
<ACCEPTANCE-DATETIME>20051222180501
ACCESSION NUMBER:		0001209191-05-065249
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20051220
FILED AS OF DATE:		20051222
DATE AS OF CHANGE:		20051222

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			HALLADOR PETROLEUM CO
		CENTRAL INDEX KEY:			0000788965
		STANDARD INDUSTRIAL CLASSIFICATION:	CRUDE PETROLEUM & NATURAL GAS [1311]
		IRS NUMBER:				841014610
		STATE OF INCORPORATION:			CO
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1660 LINCOLN ST STE 2700
		CITY:			DENVER
		STATE:			CO
		ZIP:			80264
		BUSINESS PHONE:		3038395505

	MAIL ADDRESS:	
		STREET 1:		1660 LINCOLN STREET
		STREET 2:		SUITE 2700
		CITY:			DENVER
		STATE:			CO
		ZIP:			80264

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	KIMBARK OIL & GAS CO /CO/
		DATE OF NAME CHANGE:	19900102

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	KIMBARK INC
		DATE OF NAME CHANGE:	19860624

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			YORKTOWN ENERGY PARTNERS II LP
		CENTRAL INDEX KEY:			0001050354

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-14731
		FILM NUMBER:		051283240

	BUSINESS ADDRESS:	
		STREET 1:		535 MADISON AVENUE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
		BUSINESS PHONE:		2129067000

	MAIL ADDRESS:	
		STREET 1:		535 MADISON AVENUE
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10022
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>bod31431_bod2hpc.xml
<DESCRIPTION>MAIN DOCUMENT DESCRIPTION
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-12-20</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0000788965</issuerCik>
        <issuerName>HALLADOR PETROLEUM CO</issuerName>
        <issuerTradingSymbol>HCPO.OB</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001050354</rptOwnerCik>
            <rptOwnerName>YORKTOWN ENERGY PARTNERS II LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>410 PARK AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2>19TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10022</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2005-12-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2278500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>2.20</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <ownerSignature>
        <signatureName>/s/ W. Howard Keenan, Jr.</signatureName>
        <signatureDate>2005-12-21</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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