-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 F52M9qMKfKL2vHIasly2MANJ7piXtjMXT2oWGMOM1VbebtwPLnegLIYxDBDRsbfy
 kdIuS0b9yvhYNo0l5Uamtw==

<SEC-DOCUMENT>0001214412-10-000032.txt : 20101110
<SEC-HEADER>0001214412-10-000032.hdr.sgml : 20101110
<ACCEPTANCE-DATETIME>20101110163432
ACCESSION NUMBER:		0001214412-10-000032
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20101108
FILED AS OF DATE:		20101110
DATE AS OF CHANGE:		20101110

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BRIGHAM DAVID T
		CENTRAL INDEX KEY:			0001214412

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-34224
		FILM NUMBER:		101180468

	BUSINESS ADDRESS:	
		STREET 1:		6300 BRIDGE POINT PARKWAY
		STREET 2:		BLDG 2 SUITE 500
		CITY:			AUSTIN
		STATE:			TX
		ZIP:			78730
		BUSINESS PHONE:		5124273300

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BRIGHAM EXPLORATION CO
		CENTRAL INDEX KEY:			0001034755
		STANDARD INDUSTRIAL CLASSIFICATION:	CRUDE PETROLEUM & NATURAL GAS [1311]
		IRS NUMBER:				752692967
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		6300 BRIDGE POINT PARKWAY
		STREET 2:		BLDG 2 SUITE 500
		CITY:			AUSTIN
		STATE:			TX
		ZIP:			78730
		BUSINESS PHONE:		5124273300

	MAIL ADDRESS:	
		STREET 1:		6300 BRIDGE POINT PARKWAY
		STREET 2:		BLDG 2 SUITE 500
		CITY:			AUSTIN
		STATE:			TX
		ZIP:			78730
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-11-08</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001034755</issuerCik>
        <issuerName>BRIGHAM EXPLORATION CO</issuerName>
        <issuerTradingSymbol>BEXP</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001214412</rptOwnerCik>
            <rptOwnerName>BRIGHAM DAVID T</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>6300 BRIDGE POINT PKWY., BLDG.2, STE.500</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>AUSTIN</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>78730</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Executive V.P. Land &amp; Admin.</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $.01</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2010-11-08</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>48000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.145</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>96536</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $.01</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2010-11-08</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>16000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>5.08</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>112536</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $.01</value>
                <footnoteId id="F2"/>
            </securityTitle>
            <transactionDate>
                <value>2010-11-08</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>64000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>23.3626</value>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>48536</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, par value $.01</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>88400</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>As Custodian</value>
                    <footnoteId id="F6"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Incentive Stock Option (right to buy)</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>6.145</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2010-11-08</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>48000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2007-09-14</value>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <value>2013-09-14</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock, par value $.01 per share</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>48000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>12000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Incentive Stock Options (right to buy)</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>5.08</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2010-11-08</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>16000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2009-10-10</value>
                <footnoteId id="F5"/>
            </exerciseDate>
            <expirationDate>
                <value>2015-10-10</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock, par value $.01 per share</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>16000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>24000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Exercise of employee stock options to purchase company stock pursuant to reporting person's existing 10b5-1 Trading Plan.</footnote>
        <footnote id="F2">Sale of common stock acquired as a result of the exercise of employee stock options pursuant to the reporting person's existing 10b5-1 Trading Plan.</footnote>
        <footnote id="F3">$23.3626 was the weighted average price for the reported transaction.  The prices ranged from a low of $23.075 per share to a high of $23.54 per share.  Upon request, the reporting person will provide to the SEC staff, the issuer or any security holder of the issuer full information regarding the number of shares sold at each specific price.</footnote>
        <footnote id="F4">The options vest in five equal annual installments beginning 9/14/2007.</footnote>
        <footnote id="F5">The options vest in five equal annual installments beginning 10/10/2009.</footnote>
        <footnote id="F6">Shares held as custodian under the Texas Uniform Transfers to Minors Act for the children of Ben M. Brigham and Anne L. Brigham.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>David T. Brigham</signatureName>
        <signatureDate>2010-11-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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