POWER OF ATTORNEY

            Know all by these presents, that the undersigned hereby
constitutes and appoints each of Daniel S. Kuntz, Julie A. Krenz,
and Nikki L. Ferderer, signing singly, the undersigned's true
and lawful attorney-in-fact to:

(1) execute for and on behalf of the undersigned, in the
undersigned's capacity as an officer and/or director of MDU
Resources Group, Inc. (the "Company"), Forms 3, 4, and 5 in
accordance with Section 16(a) of the Securities Exchange Act
of 1934 and the rules thereunder;

(2) do and perform any and all acts for and on behalf of the
undersigned which may be necessary or desirable to complete and
execute any such Form 3, 4, or 5 and timely file such form with
the United States Securities and Exchange Commission and any
stock exchange or similar authority; and

(3) take any other action of any type whatsoever in connection
with the foregoing which, in the opinion of such attorney-in-fact,
may be of benefit to, in the best interest of, or legally required
by, the undersigned, it being understood that the documents executed
by such attorney-in-fact on behalf of the undersigned pursuant to
this Power of Attorney shall be in such form and shall contain such
terms and conditions as such attorney-in-fact's discretion.

            The undersigned hereby grants to each such attorney-
in-fact full power and authority to do and perform any and every act
and thing whatsoever requisite, necessary, or proper to be done in
the exercise of any of the rights and powers herein granted, as
fully to all intents and purposes as the undersigned might or could
do if personally present, with full power of substitution or
revocation, hereby ratifying and confirming all that such attorney-
in-fact, or such attorney-in-fact's substitute or substitutes, shall
lawfully do or cause to be done by virtue of this power of attorney
and the rights and powers herein granted.  The undersigned
acknowledges that the foregoing attorneys-in-fact, in serving in such
capacity at the request of the undersigned, are not assuming, nor
is the Company assuming, any of the undersigned's responsibilities
to comply with Section 16 of the Securities Exchange Act of 1934.

            This Power of Attorney shall remain in full force and effect
until the undersigned is no longer required to file Forms 3, 4, and 5
with respect to the undersigned's holdings of and transactions in
securities issued by the Company, unless earlier revoked by the
undersigned in a signed writing delivered to the foregoing
attorneys-in-fact.

            IN WITNESS WHEREOF, the undersigned has caused this Power
of Attorney to be executed as of August 9, 2016.

					/s/ Mark A. Hellerstein
					    Mark A. Hellerstein