Exhibit 5(a)

                    [LETTERHEAD OF MDU RESOURCES GROUP, INC.]


                                November 18, 2002


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-3 (the "Registration
Statement") to be filed on or about the date hereof with the Securities and
Exchange Commission (the "Commission") by MDU Resources Group, Inc. (the
"Company") pursuant to Rule 462(b) under the Securities Act of 1933, as amended
(the "Securities Act"), contemplating the issuance and sale, from time to time,
of up to 400,363 shares of its Common Stock, par value $1.00 per share (the
"Shares"), and the Preference Share Purchase Rights appurtenant thereto (the
"Rights"), which will be sold by the Company, it is my opinion that:

     1. The Company is a corporation validly organized and existing under the
laws of the state of Delaware and is duly qualified to do business as a foreign
corporation in the states of Minnesota, Montana, North Dakota, South Dakota and
Wyoming.

     2. When the Company's Board of Directors or a duly authorized committee
thereof shall have approved the issuance and sale of the Shares by the Company
and upon the issuance and delivery thereof and the receipt by the Company of the
consideration therefor, as contemplated by the Registration Statement, the
Shares will be validly issued, fully paid and non-assessable.

     3. The issuance of the Rights has been validly authorized by all necessary
corporate action on the part of the Company and, when issued in accordance with
the Rights Agreement, dated as of November 12, 1998, between the Company and
Wells Fargo Bank Minnesota N.A., as Rights Agent, will be validly issued.

     In rendering the opinion set forth in paragraph "2" above, I have
necessarily assumed that the 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 by the
Company of the Shares remain in full force and effect.

     I am a member of the North Dakota and Montana Bars and do not hold myself
out as an expert on the laws of the States of Minnesota, Wyoming or South
Dakota, but I have made a study through counsel located in such jurisdictions or





otherwise of the laws of such jurisdictions insofar as such laws are involved in
the conclusions expressed in this opinion. 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 Thelen
Reid & Priest LLP, 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 use of my name, as counsel, therein. In giving
the foregoing consent, I do not thereby admit that I am in the category of
persons whose consent is required under Section 7 of the Securities Act or the
rules and regulations of the Commission thereunder.

                                                   Very truly yours,

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