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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 ESDK2Zba0geo4tMPJYyOvWI/ptVn0Rqj2l0JV3zECTMcAv1ffCQjVnOf9XCt6Er9
 9UDJJrgTD8Sc3n6mQwzieA==

<SEC-DOCUMENT>0000043704-05-000009.txt : 20050217
<SEC-HEADER>0000043704-05-000009.hdr.sgml : 20050217
<ACCEPTANCE-DATETIME>20050217135010
ACCESSION NUMBER:		0000043704-05-000009
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20050215
FILED AS OF DATE:		20050217
DATE AS OF CHANGE:		20050217

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			GREEN MOUNTAIN POWER CORP
		CENTRAL INDEX KEY:			0000043704
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRIC SERVICES [4911]
		IRS NUMBER:				030127430
		STATE OF INCORPORATION:			VT
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		163 ACORN LANE
		STREET 2:		.
		CITY:			COLCHESTER
		STATE:			VT
		ZIP:			05446
		BUSINESS PHONE:		8028645731

	MAIL ADDRESS:	
		STREET 1:		163 ACORN LANE
		STREET 2:		.
		CITY:			COLCHESTER
		STATE:			VT
		ZIP:			05446

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			POWELL MARY G
		CENTRAL INDEX KEY:			0001247234

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08291
		FILM NUMBER:		05623519

	MAIL ADDRESS:	
		STREET 1:		GREEN MOUNTAIN POWER CORP
		STREET 2:		163 ACORN LANE
		CITY:			COLCHESTER
		STATE:			VT
		ZIP:			05446
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-02-15</periodOfReport>

    <issuer>
        <issuerCik>0000043704</issuerCik>
        <issuerName>GREEN MOUNTAIN POWER CORP</issuerName>
        <issuerTradingSymbol>GMP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001247234</rptOwnerCik>
            <rptOwnerName>POWELL MARY G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>163 ACORN LANE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>COLCHESTER</rptOwnerCity>
            <rptOwnerState>VT</rptOwnerState>
            <rptOwnerZipCode>05446</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chief Operating Officer</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2005-02-15</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1310</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>29.165</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6590</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2390.9218</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By 401(k) Plan</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Disposition represents withholding of common shares to satisfy tax withholding obligations associated with the vesting of stock units granted on February 9, 2004.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Donald J. Rendall, Jr., Attorney-In-Fact</signatureName>
        <signatureDate>2005-02-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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