EXHIBIT 5(a)










                                                                    Exhibit 5(a)



                               Lester H. Loble, II
                  Vice President, General Counsel and Secretary
                            MDU Resources Group, Inc.
                               Schuchart Building
                             918 East Divide Avenue
                                  P.O. Box 5650
                        Bismarck, North Dakota 58506-5650




                                                   September 28, 2001



MDU Resources Group, Inc.
Schuchart Building
918 East Divide Avenue
P.O. Box 5650
Bismarck, North Dakota  58506-5650

Ladies and Gentlemen:

     With reference to the Registration Statement on Form S-8 (the "Registration
Statement") to be filed on or about the date hereof with the Securities and
Exchange Commission by MDU Resources Group, Inc. (the "Company") under the
Securities Act of 1933, as amended, (the "Securities Act"), and pursuant to
which the Company intends to register 2,600,000 additional shares of its Common
Stock, par value $1.00 (the "Stock") and the Preference Share Purchase Rights
attached thereto (the "Rights"), for offer and sale in connection with the MDU
Resources Group, Inc. 401(k) Retirement Plan (the "Plan"), it is my opinion
that:

     1.   When

          (a)  appropriate authorizations by the Federal Energy Regulatory
               Commission, the Montana Public Service Commission and the Public
               Service Commission of Wyoming with respect to the issuance and
               sale of the Stock shall have been granted,

          (b)  the Company's Board of Directors or a duly authorized committee
               thereof shall have approved the issuance and sale of the Stock by
               the Company,





          (c)  the Registration Statement shall have become effective under the
               Securities Act and

          (d)  the Stock shall have been duly authorized, issued and delivered
               for the consideration set forth in the Plan and in accordance
               with the actions hereinabove mentioned,

the Stock will be duly authorized, validly issued, fully paid and
non-assessable.

     2. The Rights, when issued as contemplated by the Rights Agreement, dated
as of November 12, 1998, between the Company and Norwest Bank Minnesota, N.A.,
as Rights Agent, will be validly issued and will represent legally binding
obligations of the Company under the laws of the State of Delaware.

     I am a member of the North Dakota and Montana Bars and do not hold myself
out as an expert on the laws of any other jurisdiction, but I have made a study
through counsel located in such jurisdictions or otherwise of such jurisdictions
insofar as such laws are involved in the conclusions expressed in this opinion.
Except as set forth in paragraph 1(a) above, my opinions expressed above are
limited to the laws of the States of North Dakota and Montana. Insofar as the
opinions expressed herein relate to the General Corporation Law of the State of
Delaware, the applicable provisions of the Delaware Constitution and the
reported judicial decisions interpreting the Delaware laws, or the Federal laws
of the United States of America, I have relied on the opinion of even date
herewith of LeBoeuf, Lamb, Greene & MacRae, L.L.P., counsel to the Company,
which opinion is to be filed as an exhibit to the Registration Statement.

     I hereby consent to the use of this opinion as an exhibit to the
Registration Statement and to the reference to me therein.

                                                 Very truly yours,

                                                 /s/ Lester H. Loble, II
                                                 Lester H. Loble, II
                                                 Vice President, General
                                                 Counsel and Secretary