CERTIFICATION


I, Martin A. White, certify that:

  1. I have reviewed this quarterly report on Form 10-Q
     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)) 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) 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

       (c) 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 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:  August 6, 2004


 /s/ Martin A. White
Martin A. White
Chairman of the Board, President
  and Chief Executive Officer