-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 R3grnNpmbzJxsu9OLuJ/d19zf5v3So6huwdeuJHL8dLLcekSDCxf/JGAjDIDPxU8
 Zn/uhRvoZPrOPrENYpInxA==

<SEC-DOCUMENT>0000067716-08-000209.txt : 20081211
<SEC-HEADER>0000067716-08-000209.hdr.sgml : 20081211
<ACCEPTANCE-DATETIME>20081211195113
ACCESSION NUMBER:		0000067716-08-000209
CONFORMED SUBMISSION TYPE:	3/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20071001
FILED AS OF DATE:		20081211
DATE AS OF CHANGE:		20081211

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MDU RESOURCES GROUP INC
		CENTRAL INDEX KEY:			0000067716
		STANDARD INDUSTRIAL CLASSIFICATION:	MINING, QUARRYING OF NONMETALLIC MINERALS (NO FUELS) [1400]
		IRS NUMBER:				410423660
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1200 WEST CENTURY AVENUE
		CITY:			BISMARCK
		STATE:			ND
		ZIP:			58506-5650
		BUSINESS PHONE:		701-530-1059

	MAIL ADDRESS:	
		STREET 1:		1200 WEST CENTURY AVENUE
		CITY:			BISMARCK
		STATE:			ND
		ZIP:			58506-5650

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MONTANA DAKOTA UTILITIES CO
		DATE OF NAME CHANGE:	19850429

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Del Vecchio Mark A
		CENTRAL INDEX KEY:			0001414288

	FILING VALUES:
		FORM TYPE:		3/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-03480
		FILM NUMBER:		081244606

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		701-530-1015

	MAIL ADDRESS:	
		STREET 1:		P O BOX 5650
		CITY:			BISMARCK
		STATE:			ND
		ZIP:			58506-5650
</SEC-HEADER>
<DOCUMENT>
<TYPE>3/A
<SEQUENCE>1
<FILENAME>doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0203</schemaVersion>

    <documentType>3/A</documentType>

    <periodOfReport>2007-10-01</periodOfReport>

    <dateOfOriginalSubmission>2007-10-04</dateOfOriginalSubmission>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0000067716</issuerCik>
        <issuerName>MDU RESOURCES GROUP INC</issuerName>
        <issuerTradingSymbol>MDU</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001414288</rptOwnerCik>
            <rptOwnerName>Del Vecchio Mark A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>MDU RESOURCES GROUP, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>P. O. BOX 5650</rptOwnerStreet2>
            <rptOwnerCity>BISMARCK</rptOwnerCity>
            <rptOwnerState>ND</rptOwnerState>
            <rptOwnerZipCode>58506-5650</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>VP - Human Resources</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1837</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The amount of Securities Beneficially Owned of 1,124 as originally reported was overstated by 411 shares.  Form 4's filed since the Form 3 should also be reduced by 411 shares.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>MarkA.Del Vecchio</signatureName>
        <signatureDate>2008-12-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----