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<SEC-DOCUMENT>0000898080-07-000053.txt : 20070301
<SEC-HEADER>0000898080-07-000053.hdr.sgml : 20070301
<ACCEPTANCE-DATETIME>20070301120408
ACCESSION NUMBER:		0000898080-07-000053
CONFORMED SUBMISSION TYPE:	10-K/A
PUBLIC DOCUMENT COUNT:		4
CONFORMED PERIOD OF REPORT:	20061231
FILED AS OF DATE:		20070301
DATE AS OF CHANGE:		20070301

FILER:

	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

	FILING VALUES:
		FORM TYPE:		10-K/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-03480
		FILM NUMBER:		07661473

	BUSINESS ADDRESS:	
		STREET 1:		1200 WEST CENTURY AVENUE
		CITY:			BISMARCK
		STATE:			ND
		ZIP:			58506-5650
		BUSINESS PHONE:		701-530-1013

	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
</SEC-HEADER>
<DOCUMENT>
<TYPE>10-K/A
<SEQUENCE>1
<FILENAME>form10ka.txt
<DESCRIPTION>FORM 10-K/A
<TEXT>
                 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549


                                   FORM 10-K/A
                                (Amendment No. 1)


     [X]        ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF
                       THE SECURITIES EXCHANGE ACT OF 1934

                   For the fiscal year ended December 31, 2006

                                       OR

     [ ]      TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF
                       THE SECURITIES EXCHANGE ACT OF 1934

         For the transition period from _____________ to ______________

                          Commission file number 1-3480

                            MDU Resources Group, Inc.
             (Exact name of registrant as specified in its charter)

      Delaware                                         41-0423660
 (State or other jurisdiction of                    (I.R.S. Employer
  incorporation or organization)                    Identification No.)

                            1200 West Century Avenue
                                  P.O. Box 5650
                        Bismarck, North Dakota 58506-5650
                    (Address of principal executive offices)
                                   (Zip Code)

                          (701) 530-1000 (Registrant's
                     telephone number, including area code)


Securities registered pursuant to Section 12(b) of the Act:

                                                   Name of each exchange
             Title of each class                    on which registered
             -------------------                    -------------------
        Common Stock, par value $1.00             New York Stock Exchange
    and Preference Share Purchase Rights

<PAGE>

Securities registered pursuant to Section 12(g) of the Act:

                         Preferred Stock, par value $100
                         -------------------------------
                                (Title of Class)

Indicate by check mark if the registrant is a well-known seasoned issuer, as
defined in Rule 405 of the Securities Act. Yes |X| No | |

Indicate by check mark if the registrant is not required to file reports
pursuant to Section 13 or Section 15(d) of the Exchange Act. Yes | | No |X|

Indicate by check mark whether the registrant (1) has filed all reports required
to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during
the preceding 12 months (or for such shorter period that the registrant was
required to file such reports), and (2) has been subject to such filing
requirements for the past 90 days. Yes |X| No | |

Indicate by check mark if disclosure of delinquent filers pursuant to Item 405
of Regulation S-K is not contained herein, and will not be contained, to the
best of the registrant's knowledge, in definitive proxy or information
statements incorporated by reference in Part III of this Form 10-K or any
amendment to this Form 10-K. |X|

Indicate by check mark whether the registrant is a large accelerated filer, an
accelerated filer, or a non-accelerated filer. See definition of "accelerated
filer and large accelerated filer" in Rule 12b-2 of the Exchange Act (Check
one):

Large accelerated filer |X|  Accelerated filer | |  Non-accelerated filer | |

Indicate by check mark whether the registrant is a shell company (as defined in
Rule 12b-2 of the Act). Yes | | No |X|

State the aggregate market value of the voting common stock held by
nonaffiliates of the registrant as of June 30, 2006: $4,393,239,107.

Indicate the number of shares outstanding of each of the registrant's classes of
common stock, as of February 12, 2007: 181,147,966 shares.

DOCUMENTS INCORPORATED BY REFERENCE
Portions of the registrant's 2007 Proxy Statement are incorporated by reference
in Part III, Items 10, 11, 12, 13 and 14 of this Report.


<PAGE>


                                Explanatory Note

The information contained in Items 10, 11 and 13 in the Annual Report on Form
10-K filed on February 21, 2007 did not incorporate by reference all required
information from the Company's 2007 Proxy Statement.


                                    PART III

ITEM 10.  DIRECTORS, EXECUTIVE OFFICERS AND CORPORATE GOVERNANCE

The information required by this item is included under the captions "Item 1.
Election of Directors," "Continuing Incumbent Directors," "Information
Concerning Executive Officers," the first and third paragraphs under "Corporate
Governance - Audit Committee," "Corporate Governance - Code of Conduct" and
"Section 16(a) Beneficial Ownership Reporting Compliance" in the Proxy
Statement, which information is incorporated herein by reference.

ITEM 11. EXECUTIVE COMPENSATION

The information required by this item is included under the caption "Executive
Compensation" in the Proxy Statement, which information is incorporated herein
by reference.

ITEM 13. CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS, AND DIRECTOR
INDEPENDENCE

The information required by this item is included under the captions "Related
Person Disclosure" and "Corporate Governance - Director Independence" in the
Proxy Statement, which information is incorporated herein by reference.

                                     PART IV

ITEM 15. EXHIBITS AND FINANCIAL STATEMENT SCHEDULES

(a)     FINANCIAL STATEMENTS, FINANCIAL STATEMENT SCHEDULES AND EXHIBITS

3.  Exhibits

Exhibits filed herewith:

31(a)     Certification of Chief Executive Officer filed pursuant to Section 302
          of the Sarbanes-Oxley Act of 2002

31(b)     Certification of Chief Financial Officer filed pursuant to Section 302
          of the Sarbanes-Oxley Act of 2002

                                       1
<PAGE>

32        Certification of Chief Executive Officer and Chief Financial Officer
          furnished pursuant to 18 U.S.C. Section 1350, as adopted pursuant to
          Section 906 of the Sarbanes-Oxley Act of 2002

                                       2
<PAGE>


                                   SIGNATURES

Pursuant to the requirements of Section 13 or 15(d) of the Securities Exchange
Act of 1934, the registrant has duly caused this amendment to be signed on its
behalf by the undersigned, thereunto duly authorized.

                                             MDU RESOURCES GROUP, INC.

Date:  March 1, 2007                         By: /s/ Vernon A. Raile
                                                 -------------------
                                                 Vernon A. Raile
                                                 Executive Vice President,
                                                 Treasurer and Chief Financial
                                                 Officer

                                       3
<PAGE>



                                  EXHIBIT INDEX

Exhibit Number      Description of Exhibit

31(a)               Certification of Chief Executive Officer filed pursuant to
                    Section 302 of the Sarbanes-Oxley Act of 2002

31(b)               Certification of Chief Financial Officer filed pursuant to
                    Section 302 of the Sarbanes-Oxley Act of 2002

32                  Certification of Chief Executive Officer and Chief Financial
                    Officer furnished pursuant to 18 U.S.C. Section 1350, as
                    adopted pursuant to Section 906 of the Sarbanes-Oxley Act of
                    2002

</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-31.A
<SEQUENCE>2
<FILENAME>ex31-a.txt
<DESCRIPTION>CERTIFICATION
<TEXT>
                                                                   Exhibit 31(a)
                                  CERTIFICATION

I, Terry D. Hildestad, certify that:

1.        I have reviewed this annual report on Form 10-K for the year ended
          December 31, 2006, as amended by Form 10-K/A (Amendment No. 1) of MDU
          Resources Group, Inc.;

2.        Based on my knowledge, this report does not contain any untrue
          statement of a material fact or omit to state a material fact
          necessary to make the statements made, in light of the circumstances
          under which such statements were made, not misleading with respect to
          the period covered by this report;

3.        Based on my knowledge, the financial statements, and other financial
          information included in this report, fairly present in all material
          respects the financial condition, results of operations and cash flows
          of the registrant as of, and for, the periods presented in this
          report;

4.        The registrant's other certifying officer and I are responsible for
          establishing and maintaining disclosure controls and procedures (as
          defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal
          control over financial reporting (as defined in Exchange Act Rules
          13a-15(f) and 15d-15(f)) for the registrant and have:

          (a)       Designed such disclosure controls and procedures, or caused
                    such disclosure controls and procedures to be designed under
                    our supervision, to ensure that material information
                    relating to the registrant, including its consolidated
                    subsidiaries, is made known to us by others within those
                    entities, particularly during the period in which this
                    report is being prepared;

          (b)       Designed such internal control over financial reporting, or
                    caused such internal control over financial reporting to be
                    designed under our supervision, to provide reasonable
                    assurance regarding the reliability of financial reporting
                    and the preparation of financial statements for external
                    purposes in accordance with generally accepted accounting
                    principles;

          (c)       Evaluated the effectiveness of the registrant's disclosure
                    controls and procedures and presented in this report our
                    conclusions about the effectiveness of the disclosure
                    controls and procedures, as of the end of the period covered
                    by this report based on such evaluation; and

          (d)       Disclosed in this report any change in the registrant's
                    internal control over financial reporting that occurred
                    during the registrant's most recent fiscal quarter (the
                    registrant's fourth fiscal quarter in the case of an annual
                    report) that has materially affected, or is reasonably
                    likely to materially affect, the registrant's internal
                    control over financial reporting; and

5.        The registrant's other certifying officer and I have disclosed, based
          on our most recent evaluation of internal control over financial
          reporting, to the registrant's auditors and the

<PAGE>

          audit committee of the registrant's board of directors (or persons
          performing the equivalent functions):

          (a)       All significant deficiencies and material weaknesses in the
                    design or operation of internal control over financial
                    reporting which are reasonably likely to adversely affect
                    the registrant's ability to record, process, summarize and
                    report financial information; and

          (b)       Any fraud, whether or not material, that involves management
                    or other employees who have a significant role in the
                    registrant's internal control over financial reporting.


Date: March 1, 2007                        /s/ Terry D. Hildestad
                                           -------------------------------------
                                           Terry D. Hildestad
                                           President and Chief Executive Officer
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-31.B
<SEQUENCE>3
<FILENAME>ex31-b.txt
<DESCRIPTION>CERTIFICATION
<TEXT>
                                                                   Exhibit 31(b)
                                  CERTIFICATION

I, Vernon A. Raile, certify that:

1.        I have reviewed this annual report on Form 10-K for the year ended
          December 31, 2006, as amended by Form 10-K/A (Amendment No. 1) of MDU
          Resources Group, Inc.;

2.        Based on my knowledge, this report does not contain any untrue
          statement of a material fact or omit to state a material fact
          necessary to make the statements made, in light of the circumstances
          under which such statements were made, not misleading with respect to
          the period covered by this report;

3.        Based on my knowledge, the financial statements, and other financial
          information included in this report, fairly present in all material
          respects the financial condition, results of operations and cash flows
          of the registrant as of, and for, the periods presented in this
          report;

4.        The registrant's other certifying officer and I are responsible for
          establishing and maintaining disclosure controls and procedures (as
          defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal
          control over financial reporting (as defined in Exchange Act Rules
          13a-15(f) and 15d-15(f)) for the registrant and have:

          (a)       Designed such disclosure controls and procedures, or caused
                    such disclosure controls and procedures to be designed under
                    our supervision, to ensure that material information
                    relating to the registrant, including its consolidated
                    subsidiaries, is made known to us by others within those
                    entities, particularly during the period in which this
                    report is being prepared;

          (b)       Designed such internal control over financial reporting, or
                    caused such internal control over financial reporting to be
                    designed under our supervision, to provide reasonable
                    assurance regarding the reliability of financial reporting
                    and the preparation of financial statements for external
                    purposes in accordance with generally accepted accounting
                    principles;

          (c)       Evaluated the effectiveness of the registrant's disclosure
                    controls and procedures and presented in this report our
                    conclusions about the effectiveness of the disclosure
                    controls and procedures, as of the end of the period covered
                    by this report based on such evaluation; and

          (d)       Disclosed in this report any change in the registrant's
                    internal control over financial reporting that occurred
                    during the registrant's most recent fiscal quarter (the
                    registrant's fourth fiscal quarter in the case of an annual
                    report) that has materially affected, or is reasonably
                    likely to materially affect, the registrant's internal
                    control over financial reporting; and

5.        The registrant's other certifying officer and I have disclosed, based
          on our most recent evaluation of internal control over financial
          reporting, to the registrant's auditors and the

<PAGE>

          audit committee of the registrant's board of directors (or persons
          performing the equivalent functions):

          (a)       All significant deficiencies and material weaknesses in the
                    design or operation of internal control over financial
                    reporting which are reasonably likely to adversely affect
                    the registrant's ability to record, process, summarize and
                    report financial information; and

          (b)       Any fraud, whether or not material, that involves management
                    or other employees who have a significant role in the
                    registrant's internal control over financial reporting.

Date: March 1, 2007                         /s/ Vernon A. Raile
                                            ------------------------------------
                                            Vernon A. Raile
                                            Executive Vice President, Treasurer
                                               and Chief Financial Officer
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-32
<SEQUENCE>4
<FILENAME>ex32.txt
<DESCRIPTION>SECTION 1350 CERTIFICATION
<TEXT>
                                                                      Exhibit 32

                CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350,
                       AS ADOPTED PURSUANT TO SECTION 906
                        OF THE SARBANES-OXLEY ACT OF 2002

          Each of the undersigned, Terry D. Hildestad, the President and Chief
Executive Officer, and Vernon A. Raile, the Executive Vice President, Treasurer
and Chief Financial Officer of MDU Resources Group, Inc. (the "Company"), DOES
HEREBY CERTIFY that:

          1. The Company's Annual Report on Form 10-K for the year ended
December 31, 2006 as amended by Form 10-K/A (Amendment No. 1) (the "Report"),
fully complies with the requirements of Section 13(a) of the Securities Exchange
Act of 1934; and

          2. Information contained in the Report fairly presents, in all
material respects, the financial condition and results of operation of the
Company.

          IN WITNESS WHEREOF, each of the undersigned has executed this
statement this 1st day of March, 2007.


                                        /s/ Terry D. Hildestad
                                        ----------------------------------------
                                        Terry D. Hildestad
                                        President and Chief Executive Officer


                                        /s/ Vernon A. Raile
                                        ----------------------------------------
                                        Vernon A. Raile
                                        Executive Vice President, Treasurer
                                           and Chief Financial Officer

A signed original of this written statement required by Section 906 has been
provided to MDU Resources Group, Inc. and will be retained by MDU Resources
Group, Inc. and furnished to the Securities and Exchange Commission or its staff
upon request.
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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