-----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,
 Jv6nJptl59wYyCNXgxvMCywmaSXuYYmi+fpF1f4jA27aqtq4YyXeeCBQma2g1Xrv
 WyksZ90hcRTmDafajk/Niw==

<SEC-DOCUMENT>0000043704-04-000058.txt : 20040721
<SEC-HEADER>0000043704-04-000058.hdr.sgml : 20040721
<ACCEPTANCE-DATETIME>20040721142731
ACCESSION NUMBER:		0000043704-04-000058
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20040719
FILED AS OF DATE:		20040721

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			COATES DAVID R
		CENTRAL INDEX KEY:			0001247220

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08291
		FILM NUMBER:		04924133

	MAIL ADDRESS:	
		STREET 1:		GREEN MOUNTAIN POWER CORP
		STREET 2:		163 ACORN LANE
		CITY:			COLCHESTER
		STATE:			VT
		ZIP:			05446

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
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>c0001247220d20040721f4f.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-07-19</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001247220</rptOwnerCik>
            <rptOwnerName>COATES DAVID R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>163 ACORN LANE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>COLCHESTER</rptOwnerCity>
            <rptOwnerState>VT</rptOwnerState>
            <rptOwnerZipCode>05446</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2004-07-19</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1100</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>9200</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Shares represent stock units that will be payable on a one-for-one basis in shares of common stock at vesting on December 31, 2004, which vesting date is subject to deferral at the election of the reporting person.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Donald J. Rendall, Jr., Attorney-In-Fact</signatureName>
        <signatureDate>2004-07-21</signatureDate>
    </ownerSignature>
</ownershipDocument>

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