Exhibit 23(b)

                                 CONSENT OF ENGINEER

               We hereby consent to the incorporation by reference in this
          Post-Effective Amendment No. 1 to the registration statement on
          Form S-8 filed by MDU Resources Group, Inc. with the Securities
          and Exchange Commission (Registration No. 333-06105) of our
          reports, each dated January 12, 1998, which appear in the MDU
          Resources Group, Inc. Annual Report on Form 10-K for the year
          ended December 31, 1997.


                                       RALPH E. DAVIS ASSOCIATES, INC.


          July 13, 1998
          Houston, Texas