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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0001140361-10-034108.txt : 20100817
<SEC-HEADER>0001140361-10-034108.hdr.sgml : 20100817
<ACCEPTANCE-DATETIME>20100817171135
ACCESSION NUMBER:		0001140361-10-034108
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20100813
FILED AS OF DATE:		20100817
DATE AS OF CHANGE:		20100817

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			OHLMACHER THOMAS M
		CENTRAL INDEX KEY:			0001194294

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-31303
		FILM NUMBER:		101023824

	MAIL ADDRESS:	
		STREET 1:		P O BOX 1400
		CITY:			RAPID CITY
		STATE:			SD
		ZIP:			57709-1400

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BLACK HILLS CORP /SD/
		CENTRAL INDEX KEY:			0001130464
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRIC SERVICES [4911]
		IRS NUMBER:				460458824
		STATE OF INCORPORATION:			SD
		FISCAL YEAR END:			0128

	BUSINESS ADDRESS:	
		STREET 1:		625 9TH STREET
		STREET 2:		PO BOX 1400
		CITY:			RAPID CITY
		STATE:			SD
		ZIP:			57709
		BUSINESS PHONE:		6057212343

	MAIL ADDRESS:	
		STREET 1:		625 9TH STREET
		STREET 2:		PO BOX 1400
		CITY:			RAPID
		STATE:			SD
		ZIP:			57709

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BLACK HILLS HOLDING CORP
		DATE OF NAME CHANGE:	20001222
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2010-08-13</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001130464</issuerCik>
        <issuerName>BLACK HILLS CORP /SD/</issuerName>
        <issuerTradingSymbol>BKH</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001194294</rptOwnerCik>
            <rptOwnerName>OHLMACHER THOMAS M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>PO BOX 1400</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>RAPID CITY</rptOwnerCity>
            <rptOwnerState>SD</rptOwnerState>
            <rptOwnerZipCode>57709</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>PRES &amp; COO NONREG ENERGY GROUP</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2010-08-13</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>236.509</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>31.20</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>44394.971</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Shares used to pay tax withholding associated with restricted stock vesting.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Lorna Zacher, by power of attorney</signatureName>
        <signatureDate>2010-08-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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