UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM 8-K

                                 CURRENT REPORT
                     Pursuant to Section 13 or 15(d) of the
                         Securities Exchange Act of 1934

         Date of Report (Date of earliest event reported): June 14, 2007

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

            Delaware                  1-3480                   41-0423660
(State or other jurisdiction of     (Commission             (I.R.S. Employer
         incorporation)             File Number)           Identification No.)

                            1200 West Century Avenue
                                  P.O. Box 5650
                        Bismarck, North Dakota 58506-5650
                    (Address of principal executive offices)
                                   (Zip Code)
        Registrant's telephone number, including area code (701) 530-1000



Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registrant under any of the
following provisions:

[ ]  Written communications pursuant to Rule 425 under the Securities Act
(17 CFR 230.425)

[ ]  Soliciting material pursuant to Rule 14a-12 under the Exchange Act
(17 CFR 240.14a-12)

[ ]  Pre-commencement communications pursuant to Rule 14d-2(b) under the
Exchange Act (17 CFR 240.14d-2(b))

[ ]  Pre-commencement communications pursuant to Rule 13e-4(c) under the
Exchange Act (17 CFR 240.13e-4(c))







ITEM 5.02 DEPARTURE OF DIRECTORS OR CERTAIN OFFICERS; ELECTION OF DIRECTORS;
APPOINTMENT OF CERTAIN OFFICERS; COMPENSATORY ARRANGEMENTS OF CERTAIN OFFICERS.

John K. Castleberry, Executive Vice President - Administration of MDU Resources
Group, Inc. (the "Company"), announced that he is retiring from the Company
effective as of the close of business on July 6, 2007 after 25 years of service.









                                   SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.


Date:  June 19, 2007

                                          MDU Resources Group, Inc.

                                          By:   /s/ Doran N. Schwartz
                                                ----------------------------
                                                 Doran N. Schwartz
                                                 Vice President and Chief
                                                 Accounting Officer