As filed with the Securities and Exchange Commission on March 10, 2003
                                                      Registration No. 333-06127
================================================================================

                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                             -----------------------


                         POST-EFFECTIVE AMENDMENT NO. 1
                                       TO
                                    FORM S-3
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933
                             -----------------------

                            MDU RESOURCES GROUP, INC.
             (Exact Name of Registrant as Specified in Its Charter)


          DELAWARE                                      41-0423660
(State or Other Jurisdiction of           (I.R.S. Employer Identification No.)
Incorporation or Organization)

                               SCHUCHART BUILDING
                      918 EAST DIVIDE AVENUE, P.O. BOX 5650
                        BISMARCK, NORTH DAKOTA 58506-5650
                                 (701) 222-7900
       (Name, Address, Including Zip Code, and Telephone Number, Including
             Area Code, of Registrant's Principal Executive Offices)

                             -----------------------

                                                                        

           MARTIN A. WHITE                         WARREN L. ROBINSON                  ELIZABETH W. POWERS, ESQ.
   Chairman of the Board, President       Executive Vice President, Treasurer    LeBoeuf, Lamb, Greene & MacRae, L.L.P.
     and Chief Executive Officer              and Chief Financial Officer                 125 West 55th Street
      MDU Resources Group, Inc.                MDU Resources Group, Inc.                New York, New York 10019
          Schuchart Building                       Schuchart Building                        (212) 424-8000
918 East Divide Avenue, P.O. Box 5650    918 East Divide Avenue, P.O. Box 5650
  Bismarck, North Dakota 58506-5650        Bismarck, North Dakota 58506-5650
            (701) 222-7900                           (701) 222-7900


         (Names, Addresses and Telephone Numbers of Agents for Service)
                             -----------------------

APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE TO PUBLIC: From time to time
after the effective date of this Registration Statement, as determined by market
conditions and other factors.

If the only securities being registered on this Form are being offered pursuant
to dividend or interest reinvestment plans, please check the following box. [ ]

If any of the securities being registered on this Form are to be offered on a
delayed or continuous basis pursuant to Rule 415 under the Securities Act of
1933, other than securities offered only in connection with dividend or interest
reinvestment plans, check the following box. [x]

If this Form is filed to register additional securities for an offering pursuant
to Rule 462(b) under the Securities Act, please check the following box and list
the Securities Act registration statement number of the earlier effective
registration statement for the same offering. [ ]

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under
the Securities Act, check the following box and list the Securities Act
registration statement number of the earlier effective registration statement
for the same offering [ ]

If delivery of the prospectus is expected to be made pursuant to Rule 434,
please check the following box. [ ]

The registrant hereby amends the registration statement on such date or dates as
may be necessary to delay its effective date until the registrant shall file a
further amendment which specifically states that this registration statement
shall thereafter become effective in accordance with Section 8(a) of the
Securities Act or until the registration statement shall become effective on
such date as the Commission, acting pursuant to said Section 8(a), may
determine.

================================================================================





                                EXPLANATORY NOTE

     This Post-Effective Amendment No. 1 is being filed for the purpose of
amending and restating the Dividend Reinvestment and Direct Stock Purchase Plan.

     The Registration Statement (No. 333-06127) as originally filed related to
the offering of 3,000,000 shares of common stock and 3,000,000 preference share
purchase rights of MDU Resources Group, Inc. issuable under the MDU Resources
Group, Inc. Automatic Dividend Reinvestment and Stock Purchase Plan. In July
1998, MDU Resources Group, Inc. effected a three-for-two common stock split.








                  Subject to Completion, dated      , 2003
PROSPECTUS

                            MDU RESOURCES GROUP, INC.
                              DIVIDEND REINVESTMENT
                                       AND
                           DIRECT STOCK PURCHASE PLAN

                                    Shares of Common Stock

     Our Dividend Reinvestment and Direct Stock Purchase Plan provides you with
a simple and convenient method of purchasing our common stock and reinvesting
cash dividends in shares of common stock without incurring brokerage commissions
or service charges. Current record holders of our common stock and preferred
stock can purchase our common stock by reinvesting all or a portion of their
cash dividends and/or making optional cash investments. In addition, persons who
are not already stockholders can purchase common stock through the plan.
Interested investors who are not already stockholders can participate in the
plan by making an initial investment of at least $250 or authorizing automatic
monthly withdrawals from a bank account of at least $25 per month for a minimum
of ten consecutive months.

     The plan allows you to:

     o    purchase our common stock through cash investments made by check or by
          automatic monthly withdrawals from a checking or savings account

     o    elect to have cash dividends paid on all or a percentage of your
          shares automatically reinvested in shares of our common stock

     o    deposit common stock certificates for credit to your account

     o    transfer shares to the existing account of another participant or to a
          newly-created account of a person not participating in the plan

     o    purchase shares for the account of another person

     o    sell shares held in the plan and obtain certificates for shares held
          in the plan and

     o    execute certain transactions by telephone or online.

     Our shares of common stock are traded on the New York Stock Exchange and
the Pacific Exchange under the symbol "MDU". The closing price of our common
stock on the New York Stock Exchange on            , 2003 was $     per share.

     To the extent required by applicable law in certain jurisdictions, shares
of common stock offered under the plan to persons not presently stockholders are
offered through Wells Fargo Investments, LLC.

                        --------------------------------

     Please review the risk factors that we have disclosed in our public filings
under the Securities Exchange Act of 1934, as amended. You should also review
the documents incorporated by reference in this prospectus for additional
factors you should consider.

     Please read this prospectus carefully before investing and retain it for
your future reference. We and the plan administrator cannot assure you of a
profit or protect you against a loss on the shares of common stock you purchase
under the plan.

                        --------------------------------

     Neither the Securities and Exchange Commission nor any state securities
commission has approved or disapproved of these securities or passed upon the
adequacy or accuracy of this prospectus. Any representation to the contrary is a
criminal offense.

                The date of this prospectus is            , 2003.






                                TABLE OF CONTENTS

                                                                            Page


      Changes to the Plan.....................................................1
      Forward-Looking Statements..............................................1
      Summary of the Plan.....................................................3
      MDU Resources Group, Inc................................................5
      Description of the Plan.................................................6
               Introduction...................................................6
               Plan Administration............................................7
               Account Forms..................................................8
               Enrollment.....................................................8
               Dividend Reinvestment..........................................9
               Optional Cash Investments.....................................10
               Changing Your Investment Options..............................11
               Purchase of Shares............................................11
               Expenses Related to Purchases.................................13
               Certificates for Shares.......................................13
               Share Transfers and Gifts.....................................14
               Sale of Shares................................................14
               Account Access................................................15
               Account Statements............................................16
               Termination of Participation..................................16
               Other Information.............................................17
      Use of Proceeds........................................................18
      Dividend Policy........................................................18
      Federal Income Tax Consequences........................................18
      Where You Can Find More Information....................................21
      Incorporation by Reference.............................................21
      Experts................................................................21
      Legal Opinions.........................................................22


     You should rely only on the information contained or incorporated in this
prospectus. We have not authorized any other person to provide you with
different information. If anyone provides you with different or inconsistent
information, you should not rely on it.

     This prospectus is not an offer to sell nor is it seeking an offer to buy
these securities in any jurisdiction where the offer or sale is not permitted.

     You should assume that the information appearing in this prospectus is
accurate as of the date on the front cover of this prospectus only. Our
business, financial condition, results of operations and prospects may have
changed since that date.


                                       i




                               Changes to the Plan

     This prospectus amends and restates our earlier Automatic Dividend
Reinvestment and Stock Purchase Plan. Amendments to the plan include:

     o    changing the name of the plan

     o    allowing participants to make optional cash investments on a more
          frequent basis

     o    increasing the amount of the required initial investment for investors
          who are not already stockholders

     o    decreasing the minimum amount of optional cash investments

     o    increasing the maximum monthly amount of optional cash investments

     o    changing the cost the plan administrator charges when a participant
          sells shares held in a plan account

     o    allowing participants to choose whether to have dividends reinvested
          or paid on all or a percentage of their shares and

     o    changing the date your bank account is debited for automatic monthly
          withdrawals.

     The amended and restated plan becomes effective on                 , 2003.

     All participants in the old plan will automatically continue in the amended
plan. A limited number of participants, who elected no dividend reinvestment or
partial dividend reinvestment on shares held outside the plan, will be asked by
the plan administrator to complete a new election form.

     Under the old plan, all dividends paid on plan shares were reinvested.
Participants could elect full, partial or no dividend reinvestment on shares
held outside the plan. Under the amended plan, a participant's dividend
reinvestment election -- full, partial or none -- will apply to both plan shares
and shares held outside the plan.

     The plan administrator will send a letter to the limited number of
participants affected by this change asking them to make a new dividend election
that will apply to both plan shares and shares held outside the plan. If a
recipient of this letter does not make an election within 30 days of receiving
the letter, the plan administrator will select partial dividend reinvestment
based on the amount the participant currently reinvests. This will be a
percentage to the nearest multiple of 10. Participants can choose to change
their dividend reinvestment option at any time by completing an account election
form (see question 14).

     In the event you are a participant in the old plan and, after reviewing
this prospectus, you do not wish to continue participation in the amended plan,
you should contact the plan administrator.

     The plan does not represent a change in our dividend policy, which will
continue to depend on future earnings, financial requirements and other factors.
The payment of dividends is at the discretion of our board of directors, which
may change the amount and timing of dividends at any time without notice.

                           Forward-Looking Statements

     This document and the documents incorporated by reference may contain
forward-looking statements within the meaning of Section 27A of the Securities
Act of 1933 or Section


                                       1




21E of the Securities Exchange Act of 1934. Forward-looking statements should be
read with the cautionary statements and risk factors included in our latest
Annual Report on Form 10-K at Item 7 -- "Management's Discussion and Analysis of
Financial Condition and Results of Operations" and in any other documents
incorporated by reference into this prospectus. Forward-looking statements are
all statements other than statements of historical fact, including without
limitation, those statements that are identified by the words "anticipates,"
"estimates," "expects," "intends," "plans," "predicts" and similar expressions.


                                       2




                               Summary of the Plan

     DIVIDEND REINVESTMENT. You may elect to reinvest cash dividends on all,
some or none of your shares of common stock, preferred stock or preferred stock
A. In this prospectus, we refer to our preferred stock and preferred stock A
collectively as our preferred stock. The plan administrator will use cash
dividends paid on shares as to which you elect reinvestment to purchase shares
of common stock, which will be added to your plan account. We will pay cash
dividends on shares as to which you do not elect reinvestment to you by check or
direct deposit (see question 10).

     OPTIONAL CASH INVESTMENTS. After enrolling in the plan, you may purchase
shares of our common stock through the plan in any amount from a minimum of $25
per investment to a maximum of $10,000 per month. You may make optional cash
investments by authorizing automatic monthly withdrawals from your bank account
or by sending a check or money order to the plan administrator at any time (see
question 13).

     ENROLLMENT. To enroll in the plan, you must complete and sign an account
authorization form and return it to the plan administrator or establish online
access and enroll over the internet (see question 7).

     INITIAL INVESTMENT. If you are not a registered owner of our common or
preferred stock, you may purchase common stock through an initial investment of
at least $250 or authorize automatic monthly withdrawals from your bank account
of at least $25 per month for a minimum of ten consecutive months (see question
8).

     PRICE OF SHARES PURCHASED THROUGH THE PLAN. The price of common stock
purchased through the plan will depend on whether the shares are purchased
directly from us or on the open market. The price per share for shares purchased
on the open market or in negotiated transactions will be the weighted average
price paid for all shares acquired by the plan during the applicable investment
period. The price of shares acquired directly from us will be the average of the
high and low sale prices on the applicable investment date (see question 16).

     FREQUENCY OF PURCHASES. The plan administrator will typically make share
purchases on (a) Tuesday of each week or, if Tuesday is not a trading day, the
next trading day following Tuesday or (b) in any week in which a cash dividend
is paid, the dividend payment date or, if the dividend payment date is not a
trading day, the next trading day following the dividend payment date (see
question 18).

     SAFEKEEPING. You may deposit common stock certificates with the plan
administrator for safekeeping. The shares represented by these certificates will
be converted to book-entry shares held in your plan account (see question 22).

     CERTIFICATE ISSUANCE. You may receive stock certificates for any whole
shares held in your plan account without charge at any time upon request (see
question 21).

     PLAN ACCOUNTS. Shares of common stock held in the plan - whether purchased
through cash contributions, acquired through dividend reinvestment, deposited
for safekeeping or otherwise - will be reflected in book-entry form in an
account in your name.

     SELLING SHARES. You may direct the plan administrator to sell shares of
common stock held in the plan account. You will be charged certain costs such as
broker's commissions and service fees in connection with sales from your plan
account (see questions 25 and 26).


                                       3




     SHARE TRANSFERS AND GIFTS. You can transfer shares from your account to
another person and/or purchase shares for others as a gift (see questions 23 and
24).


                                        4




                            MDU Resources Group, Inc.

     We are a diversified natural resource company which was incorporated under
the laws of the State of Delaware in 1924. Our principal executive offices are
at the Schuchart Building, 918 East Divide Avenue, P.O. Box 5650, Bismarck,
North Dakota 58506-5650, telephone (701) 222-7900. Our internet address is
www.mdu.com.

     Montana-Dakota Utilities Co., one of our public utility divisions, through
the electric and natural gas distribution segments, generates, transmits and
distributes electricity and distributes natural gas in the northern Great
Plains. Great Plains Natural Gas Co., another of our public utility divisions,
distributes natural gas in southeastern North Dakota and western Minnesota.
These operations also supply related value-added products and services in the
northern Great Plains.

     We, through our wholly owned subsidiary, Centennial Energy Holdings, Inc.,
own WBI Holdings, Inc., Knife River Corporation, Utility Services, Inc.,
Centennial Energy Resources LLC and Centennial Holdings Capital LLC.

     WBI Holdings is comprised of the pipeline and energy services and the
natural gas and oil production segments. The pipeline and energy services
segment provides natural gas transportation, underground storage and gathering
services through regulated and nonregulated pipeline systems primarily in the
Rocky Mountain and northern Great Plains regions of the United States. The
pipeline and energy services segment also provides energy-related management
services, including cable and pipeline magnetization and locating. The natural
gas and oil production segment is engaged in natural gas and oil acquisition,
exploration and production activities primarily in the Rocky Mountain region of
the United States and in the Gulf of Mexico.

     Knife River mines aggregates and markets crushed stone, sand, gravel and
related construction materials, including ready-mixed concrete, cement, asphalt
and other value-added products, as well as performing integrated construction
services, in the north central and western United States, including Alaska and
Hawaii.

     Utility Services is a diversified infrastructure company specializing in
electric, gas and telecommunication utility construction, as well as industrial
and commercial electrical, exterior lighting and traffic signalization
throughout most of the United States. Utility Services also provides related
specialty equipment manufacturing, sales and rental services.

     Centennial Resources owns electric generating facilities in the United
States. Electric capacity and energy produced at these facilities is sold under
long-term contracts to nonaffiliated entities. Centennial Resources also invests
in potential new growth and synergistic opportunities that are not directly
being pursued by the other business units. These activities are reflected in the
independent power production segment.

     Centennial Capital insures and reinsures various types of risks as a
captive insurer for certain of our subsidiaries. The function of the captive
program is to fund the deductible layers of the insured companies' general
liability and automobile liability coverages. Centennial Capital also owns
certain real and personal property and contract rights. These activities are
reflected in the independent power production segment.


                                       5




     We, through our wholly owned subsidiary, Centennial Energy Resources
International Inc, have an investment in an electric generating facility in
Brazil. Electric capacity and energy produced at this facility is sold under a
long-term contract to a nonaffiliated entity. Centennial International invests
in projects outside the United States which are consistent with our philosophy,
growth strategy and areas of expertise. These activities are reflected in the
independent power production segment.

                             Description of the Plan

Introduction

1.   What is the purpose of the plan?

     The purpose of the plan is to provide participants with a simple and
convenient method of automatically investing all or a portion of their cash
dividends and/or making optional cash investments to purchase shares of our
common stock, without paying brokerage commissions or service charges. In
addition, when we direct the plan administrator to purchase common stock
directly from us, the plan provides us with a cost-efficient way to raise
additional capital.

2.   What are the advantages to participating in the plan?

     Participation in the plan has the following advantages:

     o    You will not pay brokerage commissions or service fees in connection
          with purchases under the plan (see question 20).

     o    Full investment of funds is possible under the plan because the plan
          permits fractional shares, as well as whole shares, to be credited to
          your account (see question 17).

     o    Since the plan administrator holds shares in your account in
          book-entry form, you will avoid the cost and risk associated with the
          storage, loss, theft or destruction of stock certificates. You may
          receive stock certificates without charge at any time, upon request
          (see question 21).

     o    Your recordkeeping is simplified, since you will receive a statement
          of your plan account after any account activity occurs (see question
          30).

     o    You can execute certain transactions over the telephone or online (see
          questions 27 and 28).

3.   What are the disadvantages to participating in the plan?

     Participation in the plan has the following disadvantages:

     o    You will not be able to time precisely your purchases through the plan
          and will bear the market risk associated with the fluctuations in the
          price of the common stock pending investment of funds under the plan
          (see questions 18 and 19).

     o    Execution of sales of shares held in the plan may be subject to delay.
          You will bear the market risk associated with the fluctuations in the
          price of the common stock pending the sale of your shares pursuant to
          the plan (see question 25).

     o    You will not earn interest on funds held by the plan administrator
          pending their investment (see question 18).


                                       6




     o    You may not pledge the shares credited to your plan account until you
          withdraw the shares from the plan (see question 38).

     o    Plan accounts are not insured by the Securities Investor Protection
          Corporation, the Federal Deposit Insurance Corporation or any other
          entity.


Plan Administration

4.   Who administers the plan?

     Wells Fargo Shareowner Services, a division of Wells Fargo Bank Minnesota,
N.A., who we refer to in this prospectus as the plan administrator, administers
the plan. The plan administrator is responsible for enrolling new participants
in the plan, reinvesting dividends, processing optional cash investments,
processing share sale requests, depositing and safekeeping plan shares,
processing requests for certificates, and issuing account statements. You can
obtain information about the plan, the plan administrator or your plan account
by contacting the plan administrator online, by telephone or in writing.

     The plan administrator is also responsible for purchasing and selling
shares of common stock for participants' plan accounts, including the selection
of the broker or dealer through which plan purchases and sales are made. We have
no control over the times or prices at which the plan administrator effects
transactions in the open market or the selection of the broker or dealer used by
the plan administrator to effect open market transactions.

Internet addresses:

General Inquiries:  www.wellsfargo.com/shareownerservices
Account Information:  www.shareowneronline.com

Telephone/fax number:

Tel:     1-877-536-3553*
Fax:     1-651-552-6999

*Telephone hours are Monday through Friday, between the hours of 7:00 a.m. and
7:00 p.m. Central Time.

Mailing address:                            Certified/Overnight Mail:
MDU Resources Group, Inc.                   MDU Resources Group, Inc.
c/o Wells Fargo Shareowner Services         c/o Wells Fargo Shareowner Services
PO Box 64863                                161 North Concord Exchange
St. Paul, MN 55164-0863                     South St. Paul, MN 55075-1139

     When communicating with the plan administrator about an existing account,
you should provide your account number and a daytime telephone number. Be sure
also to refer to "MDU Resources Group, Inc."


                                       7



Account Forms

5.   What forms do I use to enroll in the plan, request certain transactions or
     make changes to my plan account?

     To enroll in the plan, request certain transactions or make changes to your
plan account, you should complete the appropriate account form and return it to
the plan administrator. The three different forms are explained below. You may
obtain these account forms by contacting the plan administrator by telephone, or
downloading similar forms online (see question 4). You should return all forms
to the plan administrator.

     Account Authorization Form. An account authorization form is used to enroll
in the plan and, at the time of enrollment, select a dividend reinvestment
option and, if you choose, authorize automatic monthly withdrawals and/or
authorize automated account access. An account authorization form is enclosed
with this prospectus.

     Transaction Request Form. A transaction request form is used to establish,
change or terminate automatic monthly withdrawals, make optional cash
investments, sell plan shares, deposit share certificates, request certificates
for plan shares and terminate participation in the plan. A transaction request
form is attached to each account statement mailed to participants.

     Account Election Form. An account election form is used to establish,
change or terminate automatic monthly withdrawals, change record address, make
or change dividend reinvestment elections and authorize automated account
access. You can obtain this form by contacting the plan administrator.

     You can conduct certain transactions by telephone and online without using
these account forms (see questions 27 and 28).


Enrollment

6.   Who is eligible to participate?

         Any interested investor, whether or not an existing stockholder of
record of our common or preferred stock, is eligible to participate in the plan.

7.   How do I enroll in the plan?

     You may enroll in the plan online or by completing an account authorization
form and returning it to the plan administrator.

     Online. You can enroll online at www.shareowneronline.com. At the time of
establishing online account access, you will be required to provide certain
information in order to complete the enrollment process. After establishing
online account access, you will also be able to view your account online and
conduct certain transactions online (see questions 28 and 29).

     Mail. You can also enroll by completing an account authorization form and
returning it to the plan administrator at the address set forth in question 4.
You can obtain an account authorization form at any time by going online or by
contacting the plan administrator at the address or telephone number stated in
question 4.

     In addition to the enrollment procedures described above, interested
investors who are not already stockholders of record must make an initial
investment (see question 8).


                                       8




8.   Are there any additional enrollment requirements for investors who are not
     already stockholders?

     Yes. If you are not already a stockholder of record of our common or
preferred stock, you must also make an initial investment of at least $250 or
authorize automatic monthly withdrawals from your bank account of at least $25
for a minimum of ten consecutive months (see question 13 for information about
sending checks to the plan administrator).

     The plan administrator will make every effort to process your investment
for the next investment date, provided that it receives the funds no later than
two business days prior to an investment date. Otherwise, the plan administrator
holds cash investments for investment on the next investment date (see question
18).

9.   How do I participate if my shares are held for me in the name of my bank or
     broker?

     Beneficial owners whose shares are registered in names other than their own
(for example, in the name of a broker, bank nominee or trustee) have three ways
to participate in the plan. First, beneficial owners may participate by having
at least one of their shares registered into their own names. Second, beneficial
owners can make arrangements for such participation with the broker or fiduciary
institution in whose name the stock is registered without having to transfer any
shares into their own names, if the broker or fiduciary institution agrees to
provide such service. In this case, it is the broker or fiduciary institution
that becomes the participant in the plan. Third, a beneficial owner can enroll
in the plan by completing an account authorization form and making the initial
investment that is required for investors who are not already stockholders (see
questions 7 and 8).


Dividend Reinvestment

10.  How does dividend reinvestment work?

     When you enroll in the plan, you will need to select one of the three
dividend reinvestment options offered through the plan. Your selection will
apply to shares held in your plan account and shares registered in your name.
You can change your selection at any time by following the instructions given in
question 14.

     Your three dividend reinvestment options are as follows:

     o    Full Dividend Reinvestment - You can elect to automatically reinvest
          cash dividends paid on all shares then or subsequently registered in
          your name and all shares then or subsequently held in your plan
          account, including fractional shares and shares purchased under the
          plan, in shares of common stock.

     o    Partial Dividend Reinvestment - You can elect a percentage from 10% to
          90%, in increments of 10%, of the total number of shares then or
          subsequently registered in your name and then or subsequently held in
          your plan account with respect to which you want cash dividends
          reinvested. The plan administrator will reinvest the cash dividends
          paid on the specified percentage in shares of common stock.

     o    Optional Cash Investments Only - You can elect "Optional Cash
          Investments Only." This means you will continue to receive, by check
          or direct deposit, cash dividends paid on shares then or subsequently
          registered in your name and held in your plan account.


                                       9




     If you hold both common and preferred stock, you can select one option for
your preferred stock and a different reinvestment option for your common stock
(see question 11).

     Regardless of your choice of dividend reinvestment option, you may make
optional cash investments at any time (see question 13).

11.  Can I reinvest dividends paid on shares of preferred stock?

     Holders of record of shares of our preferred stock and preferred stock A
can reinvest dividends paid on their preferred shares in shares of our common
stock. In this prospectus, we refer to our preferred stock and preferred stock A
collectively as our preferred stock. In order to reinvest dividends paid on our
preferred stock, you will need to check the box marked "preferred stock" in the
"Dividends" section of the account authorization form or account election form.

     You can only hold common stock in your plan account. You cannot purchase
shares of preferred stock under the plan or deposit certificates representing
preferred stock in your plan account.

12.  When will dividend reinvestment begin?

     If your request is received by the plan administrator on or before the
record date for a particular dividend, dividend reinvestment will begin with
respect to dividends paid on that dividend payment date. If your request is
received by the plan administrator after the record date, dividend reinvestment
will begin with the dividend payment for the next quarter. We normally pay
dividends on common and preferred stock on the first day of January, April, July
and October. The dividend record date is normally two weeks before the dividend
payment date. The payment of dividends on our common and preferred stock is at
the discretion of our board of directors.


Optional Cash Investments

13.  How can I make optional cash investments?

     After enrolling in the plan, you may make optional cash investments by
authorizing automatic monthly withdrawals from your bank account or by sending a
check or money order to the plan administrator at any time. You can vary your
optional cash investments from a minimum of $25 per investment up to a maximum
of $10,000 per month.

     Check or Money Order. When making optional cash investments by check or
money order, you must include a completed transaction request form. A
transaction request form is attached to your account statement. In addition, you
can obtain a transaction request form by contacting the plan administrator (see
question 4).

     You should make your check payable to "Shareowner Services" and include
your account number on your check. Be sure also to refer to "MDU Resources
Group, Inc." You should mail your check directly to the plan administrator at
the address set forth in question 4. The plan administrator will make every
effort to process your investment for the next investment date, provided that it
receives the funds no later than one business day prior to an investment date.
Otherwise, the plan administrator holds cash investments for investment on the
next investment date (see question 18). Do not mail checks to MDU Resources
Group, Inc.

     Your check or money order must be in U.S. dollars and drawn on a United
States bank. If you live outside the United States, contact your bank to verify
that they can provide you with a


                                       10




check that clears through a United States bank and can print the dollar amount
in U.S. funds. Due to the longer clearance period, we are unable to accept
checks through a non-United States bank. Please do not send cash.

     You may obtain a refund of any cash investment upon request received by the
plan administrator on or before the second business day prior to the date on
which it is to be invested. However, the plan administrator will not make any
refunds until it has actually collected the funds from any check or money order.

     Automatic Electronic Funds Transfer. In addition to making optional cash
investments by check or money order, you may authorize automatic monthly
withdrawals from a designated United States bank account. With automatic monthly
withdrawals, your bank account is debited four business days before the
investment date. The investment date for funds received from automatic monthly
withdrawal is the third Tuesday of each month or, if the third Tuesday is not a
trading day, the next trading day following the third Tuesday of each month.

     You will not receive any confirmation of the transfer of funds other than
as reflected in your monthly plan account statements and in your bank account
statements.

     To authorize automatic monthly withdrawals from your bank account, new
investors can go online or complete and sign the Automatic Cash Withdrawal and
Investment section of the account authorization form and return it to the plan
administrator together with a voided blank check or deposit slip for the account
from which funds are to be transferred. Current participants can go online or
use an account election form to authorize monthly automatic withdrawals. Your
automatic funds transfers will begin as soon as practicable after the plan
administrator receives your request.


Changing Your Investment Options

14.  May I change my investment options under the plan?

     Yes, you may change your investment options at any time by contacting the
plan administrator by telephone, making the request online or completing and
returning an account election form (see questions 27 and 28 regarding telephone
and online transactions).


Purchase of Shares

15.  What is the source of shares purchased under the plan?

     Shares purchased by the plan administrator under the plan may come from:

     o    our authorized but unissued shares or treasury shares of common stock

     o    shares purchased through the plan administrator on the open market or
          through negotiated transactions or

     o    a combination of the foregoing.

     We determine the source of shares used to meet the plan's requirements and,
subject to certain regulatory restrictions on the frequency with which we can
change our determination, may change such determination from time to time
without notice to plan participants.


                                       11




16.  How is the purchase price determined?

     The price of common stock purchased through the plan will depend on whether
the shares are acquired in the open market or directly from us. The price per
share for shares purchased on the open market or in negotiated transactions will
be the weighted average price paid for all shares acquired by the plan during
the applicable investment period, excluding any related brokerage commissions or
other service fees. The price of shares acquired directly from us is the average
of the high and low sale prices of the common stock, as reported on the New York
Stock Exchange Composite Tape, on the applicable investment date or, if the New
York Stock Exchange is closed on the investment date, on the next trading day
the New York Stock Exchange is open.

17.  How many shares will be purchased for me?

     The number of shares of common stock purchased for you will depend on the
amount of cash dividends being reinvested, if any, the amount of your optional
cash investments, if any, and the purchase price per share for the applicable
purchase date. The plan administrator will credit your account with that number
of whole shares and fractional shares (computed to the third decimal place)
equal to the net amount to be invested divided by the purchase price, as
determined in the manner set forth in question 16.

18.  When will the plan administrator make share purchases under the plan?

     The timing of share purchases under the plan depends on whether the plan
administrator is reinvesting dividends or investing initial and optional cash
investments.

     Dividend Reinvestment. The plan administrator expects to reinvest cash
     dividends on the applicable dividend payment date or, if the dividend
     payment date is not a trading day, the next trading day following the
     dividend payment date.

     Initial and Optional Cash Investments. The plan administrator expects to
     invest initial and optional cash investments on (a) Tuesday of each week
     or, if Tuesday is not a trading day, the next trading day following Tuesday
     or (b) in any week in which a cash dividend is paid, the dividend payment
     date or, if the dividend payment date is not a trading day, the next
     trading day following the dividend payment date.

     The plan administrator expects to complete all purchases on the dividend
payment date or investment date, but it will make all purchases within five
business days of the dividend payment date or investment date, subject to any
waiting periods required under applicable laws or stock exchange regulations.

     The plan administrator will not be liable for any claim arising out of
failure to purchase stock on a certain date or at a specific price. You bear
this risk by participating in the plan. You will not earn interest on funds held
by the plan administrator pending their investment in common stock.

19.  What discretion will I have as to matters relating to purchases?

     You will not have any discretion as to matters relating to purchases,
including determination of the number of shares, if any, to be purchased on any
day or at any time of day,


                                       12




the price to be paid for such shares, the source from which such shares are to
be purchased and when the shares are purchased.


Expenses Related to Purchases

20.  Will I incur any expenses in connection with the purchase of shares under
     the plan?

     No, you will not incur any brokerage commissions or service fees in
connection with purchases of shares under the plan. Regardless of whether the
plan administrator purchases shares directly from us, on the open market or in
negotiated transactions, we will pay any and all expenses incurred in
administering the plan, including brokerage commissions and service fees.

     If your optional cash investment is returned for any reason and the plan
administrator has already credited your account for the purchase, it will sell
the purchased shares and debit your account.

     You will incur expenses if you choose to sell shares held in your plan
account (see question 26).


Certificates for Shares

21.  Will certificates automatically be issued to me for shares purchased under
     the plan?

     No. Plan purchases are credited to your account and shown on your account
statement. You do not receive certificates for your plan shares unless you
request them. This protects against loss, theft or destruction of stock
certificates and reduces administrative costs associated with the plan.

     You may obtain certificates for some or all whole plan shares at any time
by returning the transaction request form attached to your account statement to
the plan administrator or by contacting the plan administrator by telephone (see
question 4). Any remaining whole and fractional shares will remain in your plan
account. The plan administrator will not under any circumstances issue a
certificate for a fraction of a share. Unless otherwise instructed, the plan
administrator will issue a certificate in the name or names in which your
account is registered.

22.  May I deposit certificated shares in my account?

     Yes, you may deposit with the plan administrator certificates representing
shares of common stock, whether or not the shares were acquired under the plan,
at no cost to you. To use this service, you must send your certificates to the
plan administrator, accompanied by the transaction request form attached to your
account statement. Do not endorse the certificates or complete the assignment
section on the back of the certificates.

     Shares represented by certificates deposited with the plan administrator
are credited to your account and thereafter are treated as if acquired under the
plan. You are responsible for maintaining your own records on the cost basis of
certificated shares deposited with the plan administrator.

     We recommend that you use registered mail to mail your certificates to the
plan administrator, insuring the certificates for 2% of the current market value
of the shares represented thereby. In any case, you bear the full risk of loss,
regardless of the method used, in the event the certificates are lost.


                                       13




Share Transfers and Gifts

23.  May I transfer plan shares to another person?

     Yes, you may transfer plan shares to another person subject to compliance
with any applicable laws. To do this, you must complete and sign a stock power
and return the completed executed stock power to the plan administrator. Your
signature on the stock power must be medallion guaranteed by an eligible
financial institution. You can obtain a stock power form online or by contacting
the plan administrator by telephone.

     To transfer shares to an existing account of a participant, provide the
participant's name and account number on the stock power. If the recipient is
not already a participant in the plan, you can instruct the plan administrator
to open an account for the recipient. You can do this by submitting an account
authorization form and choosing a dividend reinvestment option for the
recipient. You can also instruct the plan administrator to issue a share
certificate in the recipient's name.

     The plan administrator will use the following guidelines to execute share
transfers when specific instructions are not provided on the stock power form:

     o    When transferring shares to a plan participant, the plan administrator
          will transfer the shares to the participant's existing account.

     o    When transferring shares to a current stockholder not participating in
          the plan, the plan administrator will issue a certificate in the
          stockholder's name.

     o    When transferring shares to a person who is not a current stockholder,
          the plan administrator will automatically open an account for the
          person and enroll them in the plan. The plan administrator will select
          the "Full Dividend Reinvestment" option for this account. The
          stockholder can change this dividend reinvestment option at any time
          (see question 14).

24.  May I purchase shares for others?

     Yes, you may purchase shares of common stock for others by making cash
investments on their behalf. If the recipient is not already a participant in
the plan, you must have them complete an account authorization form and return
the completed form to the plan administrator together with either an initial
investment of at least $250 or authorization for automatic monthly withdrawals
of at least $25 for a minimum of ten consecutive months. If the recipient is
already a participant in the plan, you can submit a check of at least $25 with
the recipient's account number and name on it. Be sure also to refer to "MDU
Resources Group, Inc."


Sale of Shares

25.  How may I sell shares held in my plan account?

     You may request at any time that the plan administrator sell some or all of
the shares held in your plan account by completing a transaction request form or
submitting a written request, which includes your account number and references
"MDU Resources Group, Inc.," to the plan administrator.

     If the current market value of the shares requested to be sold is $25,000
or less, and you have previously authorized automated account access, you may
sell plan shares by contacting the


                                       14




plan administrator by telephone or requesting the sale online (see questions 27
and 28). This limitation is set to help protect against unauthorized sales. In
addition, the plan administrator, for any reason at its sole discretion and at
any time, has the right to decline to process a telephone or online sale request
and in its place require written submission of the sale request.

     The plan administrator will make every effort to process your sale order on
the next trading day following receipt of your properly completed request,
provided that instructions are received before 5:00 p.m. Central Time. Sale
requests involving multiple transactions may experience a delay. The plan
administrator will not be liable for any claim arising out of failure to sell
stock on a certain date or at a specific price. You bear this risk by
participating in the plan.

     The plan administrator will mail the proceeds from the sale of the shares,
less applicable brokerage commissions and service fees, to you after the
settlement of the sale. You can choose whether to receive the proceeds from the
sale by check payable to the name or names in which your plan account is
registered or to have the proceeds deposited directly into your United States
bank account.

26.  Will I incur any expenses in connection with the sale of shares under the
     plan?

     Yes, the plan administrator charges a service fee of $10 per transaction
and a broker commission of $0.10 per share sold. The plan administrator deducts
these fees directly from the sale check or direct bank deposit.


Account Access

27.  May I execute transactions by telephone?

     Yes. In order to conduct transactions by telephone, you will need to
authorize automated access for your account and select a personal identification
number for security purposes. Investors who do not currently participate in the
plan must use the account authorization form to establish automated access.
Current participants can establish automated access by completing the
appropriate section on the account election form. You can obtain these forms
from the plan administrator (see question 4). After you have authorized
automated access, you will be able to:

     o    change your dividend reinvestment option

     o    change the dollar amount of or terminate automatic monthly withdrawals
          from your bank account

     o    request a certificate for all or a portion of your whole plan shares,
          if the current market value of the shares to be issued is $50,000 or
          less and

     o    sell all or a portion of your plan shares, if the current market value
          of shares to be sold is $25,000 or less and you have a United States
          bank account.

28.  May I view my account information and execute transactions online?

     Yes. The plan administrator maintains an internet web site at
www.shareowneronline.com that allows you to view your account balance, stock
values, dividend information, reinvestment details and other helpful
information. You can also use online access to:

     o    enroll in the plan


                                       15




     o    change your dividend reinvestment option

     o    authorize, change or terminate automatic monthly withdrawals from your
          bank account

     o    sell all or a portion of your shares, if the current market value of
          the shares to be sold is $25,000 or less, you have a United States
          bank account and, for joint accounts, you have previously authorized
          automated account access and

     o    update your personal information.

29.  How do I establish online access?

     To establish online access or for online enrollment, go to
www.shareowneronline.com and click on "Here". Next, simply click on "First Time
Visitor" and follow the instructions provided. Participation in the plan through
the plan administrator's online services is voluntary.


Account Statements

30.  What kind of reports will I receive from the plan administrator?

     The plan administrator maintains an account for each plan participant and
sends account statements to each participant as soon as practicable after each
quarterly dividend reinvestment, after each optional cash investment and after
any transfer, sale, deposit or withdrawal of plan shares. Included as a part of
the statement is a transaction request form that you may use for requesting plan
transactions (see question 5).

     The account statements provide you with records of your purchases and sales
and should be retained for tax purposes. It is important to retain all
statements you receive as the plan administrator currently charges a fee of $15
per year to supply historical statement information.

     In addition, you will receive copies of all communications sent to all
holders of our common stock, including the annual report, the notice of annual
meeting and proxy statement, and any reports or informational statements
required by the Internal Revenue Service.


Termination of Participation

31.  When and how may I close my plan account?

     Your participation in the plan is entirely voluntary. You may terminate
your participation at any time by submitting the appropriate information on the
transaction request form attached to your account statement or by submitting a
written request, which includes your account number and references "MDU
Resources Group, Inc.," to the plan administrator. You may also terminate your
participation in the plan by telephone (see question 27).

     The plan administrator must receive termination requests at least four
business days prior to the record date to be effective as to the next cash
dividend. Any such notice the plan administrator receives after the fourth
business day prior to a dividend record date will not be effective until
dividends paid for such record date have been credited to your account. In
addition, the plan administrator must receive requests to terminate automatic
monthly withdrawals from a bank account at least 15 business days prior to the
scheduled investment date to ensure that your request is effective as to the
next optional cash investment.


                                       16




     Upon termination of your participation in the plan, unless you have
requested that some or all plan shares be sold, the plan administrator will send
you a certificate representing the number of whole shares in your plan account
and a check, less any applicable brokerage commissions and service fees, in the
amount of the market value of any fractional share. If you so request, the plan
administrator will sell some or all plan shares on your behalf. After settlement
of the sale, the plan administrator will send you a check, less any applicable
brokerage commissions and service fees and a certificate representing any whole
shares not sold.

32.  Can I re-enroll in the plan after termination?

     After termination, previous participants may re-enroll in the plan by
submitting a new account authorization form and complying with all other
enrollment procedures (see questions 7 and 8). In order to minimize unnecessary
plan administrative costs and to encourage use of the plan as a long-term
investment vehicle, we reserve the right to deny participation in the plan to
previous participants whom we or the plan administrator believe have been
excessive in their enrollment and termination.

33.  May I discontinue dividend reinvestment without closing my plan account?

     Yes, you may at any time discontinue the reinvestment of your cash
dividends on any or on all of your shares without closing your plan account by
filling out an account election form and returning it to the plan administrator
or by making the request over the telephone or online (see questions 27 and 28).


Other Information

34.  What happens if MDU Resources Group, Inc. issues a stock dividend or
     declares a stock split?

     If we declare a stock dividend or stock split, the plan administrator will
credit the number of shares of common stock distributable with respect to the
plan shares that you own as of the record date to your plan account on the
payable date.

     If you send a notice of termination or a request to sell to the plan
administrator between the record date and the payable date for a stock
distribution, the plan administrator will not process the request until the
stock distribution is credited to your account.

35.  How will shares in my account be voted?

     For each meeting of stockholders, you will receive proxy materials that
allow you to vote your plan shares by proxy. If you do not return the proxy card
or return it unsigned, none of your shares will be voted unless you vote in
person.

36.  What are the responsibilities of MDU Resources Group, Inc. and the plan
     administrator under the plan?

     We and the plan administrator will not be liable under the plan for any act
done in good faith or for any good faith omission to act, including, without
limitation, any claim of liability arising out of failure to terminate a
participant's account upon the participant's death prior to receipt of written
notice of such death, the prices at which shares are purchased or sold for your
account, the times when purchases or sales are made, check clearing or
fluctuations in the market value of our common stock. Such limitation of
liability shall not affect any rights a participant may have under the
Securities Act of 1933 or other applicable securities laws.


                                       17




     You should recognize that we and the plan administrator cannot provide you
with any assurance of a profit or protection against a loss on the shares of
common stock purchased or held for you under the plan. We and the plan
administrator do not have any responsibility beyond the exercise of ordinary
care for any action taken or omitted to be taken in connection with the plan. In
addition, we and the plan administrator do not have any duties, responsibilities
or liabilities other than those expressly set forth in the plan.

     You should be aware and are cautioned that this prospectus does not provide
you with a guarantee regarding the frequency or amount of future dividends,
which will continue to depend upon our future earnings, financial requirements
and other factors.

37.  Who determines questions of interpretation under the plan?

     We reserve the right to interpret and regulate the plan as we deem
necessary or advisable in connection with the operation of the plan.

38.  Can shares credited to my account be pledged?

     No, you may not pledge or grant a security interest in plan shares unless
certificates representing the shares have been issued by the plan administrator.

39.  Can MDU Resources Group, Inc. change or discontinue the plan?

     We reserve the right to suspend, modify or terminate the plan at any time.
Notice of such suspension, modification or termination will be sent to all
affected participants.

                                 Use of Proceeds

     We will receive no proceeds from open market or negotiated purchases of
common stock. We expect to use the proceeds from the purchase of common stock
directly from us for corporate development purposes, including, without
limitation, acquisitions made by or on behalf of our subsidiaries and other
general corporate purposes, and may include the repayment of a portion of
outstanding short-term borrowings incurred for those purposes. We have no basis
for estimating either the number of shares of common stock that will ultimately
be sold pursuant to the plan or the prices at which such shares will be sold.

                                 Dividend Policy

     It is generally our practice to pay dividends on our common and preferred
stock quarterly on the first day of January, April, July and October. The
payment of dividends is within the sole discretion of our board of directors.
The payment of dividends depends on future earnings, financial requirements and
other factors. We cannot provide you with any assurance as to the amount of
future dividends.

                         Federal Income Tax Consequences

     The following description is only a summary of certain federal income tax
consequences of participation in the plan and does not purport to be a complete
description of all federal income tax consequences of participation in the plan.
The description may be affected by future legislation, Internal Revenue Service
rulings and regulations, or court decisions. Accordingly, plan


                                       18




participants should consult with their own tax advisors with respect to the
federal, state and local tax consequences of participation in the plan. The
taxation of foreign stockholders is complicated, and, except as noted, is not
discussed in this prospectus. Accordingly, plan participants should consult with
their own tax advisors with respect to federal and foreign tax consequences of
the plan. Except as provided below, the federal income tax consequences to a
participant (including a participating corporate stockholder) in the plan, as of
the date of this prospectus, may be summarized as follows:

     (1)  With respect to reinvested cash dividends used to purchase authorized
          but unissued shares or treasury shares of common stock from us, a
          participant will be treated for federal income tax purposes as having
          received a distribution in an amount equal to the fair market value of
          the number of shares (including fractional shares) of common stock
          purchased with such reinvested cash dividends on the stock dividend
          payment date. This distribution will be treated as dividend income to
          the participant to the extent of our current and accumulated earnings
          and profits, as determined for federal income tax purposes, and as
          reported as such on Form 1099-DIV. The participant's basis in the
          shares so purchased will be equal to the fair market value of such
          shares on the dividend payment date.

     (2)  With respect to reinvested cash dividends used through the plan
          administrator to purchase shares of common stock on the open market or
          through negotiated transactions, a participant will be treated for
          federal income tax purposes as having received a distribution in an
          amount equal to the cash dividends reinvested plus any brokerage
          commissions we pay to obtain the shares. This distribution will be
          treated as dividend income to the participant to the extent of our
          current and accumulated earnings and profits, as determined for
          federal income tax purposes, and as reported as such on Form 1099-DIV.
          The participant's basis in the shares so purchased will be equal to
          the amount treated as a dividend distribution to such participant.

     (3)  A participant who purchases common stock with optional cash
          investments will recognize no taxable income upon such purchase except
          to the extent of any brokerage commissions we pay to obtain such
          shares, which amount will be treated as dividend income to the
          participant to the extent of our current and accumulated earnings and
          profits, as determined for federal income tax purposes, and as
          reported as such on Form 1099-DIV. The basis of shares purchased in
          this manner will be the amount of the optional cash investment plus
          any brokerage commissions reported on Form 1099-DIV.

     (4)  The full amount of the dividend income is taxable to a participant,
          except that in the case of a corporate stockholder such participant is
          eligible for a dividends received deduction equal to (i) 70% of the
          dividends received if the corporate stockholder owns less than 20% of
          the voting power and value of our outstanding stock (other than
          non-voting, non-convertible, non-participating preferred stock) or
          (ii) 80% of the dividends received if the corporate stockholder owns
          20% or more of the voting power and value of our outstanding stock
          (other than any non-voting, non-convertible, non-participating
          preferred stock). The dividends received deduction for corporate
          stockholders is subject to certain holding period, taxable income and
          other limitations.


                                       19




     (5)  A participant's holding period for shares of common stock acquired
          pursuant to the plan will begin on the day following the date the
          shares are credited to the participant's account.

     (6)  A participant will not realize taxable income as a result of receipt
          of certificates for whole shares of common stock credited to the
          participant's account, either upon the participant's request for those
          shares or upon withdrawal from participation in, or termination of,
          the plan.

     (7)  A participant will realize gain or loss when the shares of common
          stock held in his or her plan account are sold or exchanged and, in
          the case of a fractional share, when the participant receives a cash
          payment for a fraction of a share of common stock credited to the
          participant's account upon termination of participation in, or
          termination of, the plan. The amount of such gain or loss will be the
          difference between the amount that the participant receives for the
          shares or fraction of a share and the tax basis thereof.

     (8)  For participants who are subject to "backup" withholding, the plan
          administrator will invest in shares of common stock an amount equal to
          the cash dividends less the amount of tax required to be withheld.
          Backup withholding generally will apply if a participant (a) fails to
          furnish his or her taxpayer identification number (TIN), which for an
          individual is either his or her social security number (SSN) or
          individual taxpayer identification number (ITIN), (b) furnishes an
          incorrect TIN, (c) has been notified previously by the Internal
          Revenue Service that he or she has failed to report properly payments
          of interest and dividends, or (d) has failed to certify that he or she
          is not subject to backup withholding.

     (9)  In the case of those foreign holders of our stock whose dividends are
          subject to United States withholding tax, the plan administrator will
          apply the net amount of the dividends of such foreign stockholders,
          after the deduction of withholding taxes (including withholding taxes
          owing by reason of the purchase of shares of common stock with
          reinvested stock dividends), to the purchase of shares of common
          stock. The statements confirming purchases made for foreign
          stockholders will indicate the amount of federal tax withheld. We may
          not refund withholding taxes that we withhold, but a participant may
          claim it as a credit on an individual federal income tax return. If
          such foreign stockholders desire to invest the full amount of their
          dividends, they may mail optional cash investments to the plan
          administrator in an amount equal to the amount of the tax withheld,
          even if less than $25. In addition, withholding will occur on any sale
          of shares if a participant is subject to withholding tax. The check
          sent to the participant will be reduced by the amount of tax withheld,
          any related brokerage commission and any other costs of sale.

     (10) Foreign stockholders who check the "Optional Cash Investments Only"
          box on the account authorization form will continue to receive cash
          dividends on shares registered in their names in the same manner as if
          they were not participating in the plan. Optional cash investments
          received from them must be in United States dollars and will be
          invested in the same manner as payments from other participants.


                                       20




                       Where You Can Find More Information

     We file annual, quarterly and other reports and other information with the
Securities and Exchange Commission. You can read and copy any information filed
by us with the Securities and Exchange Commission at the Securities and Exchange
Commission's Public Reference Room at 450 Fifth Street, N.W., Washington, D.C.
20549. You can obtain additional information about the Public Reference Room by
calling the Securities and Exchange Commission at 1-800-SEC-0330.

     In addition, the Securities and Exchange Commission maintains an internet
site (http://www.sec.gov) that contains reports, proxy and information
statements, and other information regarding issuers that file electronically
with the Securities and Exchange Commission, including MDU Resources Group, Inc.
You may also access our Securities and Exchange Commission filings at our web
site at http://www.mdu.com.

                           Incorporation by Reference

     The Securities and Exchange Commission allows us to "incorporate by
reference" the information that we file with the Securities and Exchange
Commission, which means that we may disclose important information to you by
referring you to those documents. The information incorporated by reference is
an important part of this prospectus. We are incorporating by reference the
documents listed below and any future filings we make with the Securities and
Exchange Commission under Section 13(a), 13(c), 14 or 15(d) of the Securities
Exchange Act of 1934 (other than any information we furnish, rather than file,
with the Securities and Exchange Commission pursuant to certain items of Form
8-K) until we terminate this offering. Any of those future filings will update,
supersede and replace the information contained in any documents incorporated by
reference in this prospectus at the time of the future filings.

     1.   Our Annual Report on Form 10-K for the year ended December 31, 2002
          (including portions of the Annual Report to Stockholders);

     2.   Our Registration Statement on Form 8-A filed on September 21, 1994, as
          amended by Amendment No. 1 thereto, filed on March 23, 2000 and
          Amendment No. 2 thereto, filed on March 10, 2003 and any further
          amendments thereto; and

     3.   Our Registration Statement on Form 8-A filed on November 12, 1998, as
          amended by Amendment No. 1 thereto, filed on March 23, 2000 and any
          further amendments thereto.

     You may request a copy of these documents, at no cost to you, by writing or
calling the Investor Relations Department, MDU Resources Group, Inc., Schuchart
Building, 918 East Divide Avenue, P.O. Box 5650, Bismarck, North Dakota
58506-5650, telephone (701) 222-7900.

                                     Experts

     The financial statements and the related financial statement schedule
incorporated in this prospectus by reference from the Company's Annual Report on
Form 10-K for the year ended December 31, 2002 have been audited by Deloitte &
Touche LLP, independent auditors, as stated in their reports dated January 24,
2003 (which express an unqualified opinion and include


                                       21




an explanatory paragraph relating to the adoption of Statement of Financial
Accounting Standards No. 142, "Goodwill and Other Intangibles Assets"),
incorporated herein by reference, and have been so incorporated in reliance upon
the reports of such firm given upon their authority as experts in accounting and
auditing.

     The consolidated financial statements and schedule of MDU Resources Group,
Inc. as of December 31, 2001 for the years ended December 31, 2001 and 2000
incorporated in this prospectus by reference from the Company's Annual Report on
Form 10-K for the year ended December 31, 2002 were audited by Arthur Andersen
LLP, independent public accountants, as indicated in their report with respect
thereto, and have been so incorporated in reliance upon such report and upon the
authority of said firm as experts in accounting and auditing in giving said
report. On February 14, 2002, MDU Resources Group, Inc. dismissed Arthur
Andersen LLP as its independent public accounting firm, and on March 25, 2002,
the Company hired Deloitte & Touche LLP as the Company's independent auditors
for the 2002 fiscal year. On June 15, 2002, Arthur Andersen LLP was convicted on
federal charges of obstruction of justice, and in August 2002, Arthur Andersen
LLP ceased performing auditing services worldwide. These events may materially
and adversely affect the ability of Arthur Andersen LLP to satisfy all of their
existing and future obligations, including claims under the federal securities
laws. Accordingly, purchasers of common stock pursuant to the plan may be
limited in their ability to recover damages from Arthur Andersen LLP for any
claims that may arise out of Arthur Andersen LLP's audit of the Company's
financial statements. In addition, MDU Resources Group, Inc. was not able to
obtain the consent of Arthur Andersen LLP as required by Section 7 of the
Securities Act to the incorporation by reference of their report on the audited
financial statements into the registration statement. As a result of Arthur
Andersen LLP not having provided a consent, the ability of purchasers of the
common stock pursuant to the plan to assert claims and seek remedies against
Arthur Andersen LLP may be limited with respect to their report, particularly
those remedies arising under Section 11 of the Securities Act.

                                 Legal Opinions

     The validity of the common stock has been passed upon for us by Lester H.
Loble, II, Esq., Executive Vice President, General Counsel and Secretary for MDU
Resources Group, Inc., and by LeBoeuf, Lamb, Greene & MacRae, L.L.P., 125 West
55th Street, New York, New York 10019. As of March 1, 2003, Mr. Loble owned
approximately 67,953 shares of common stock, including shares that may be
acquired within 60 days pursuant to the exercise of stock options.


                                       22




                                     PART II

                     INFORMATION NOT REQUIRED IN PROSPECTUS

ITEM 16. EXHIBITS.

       Exhibit No.          Description

          *3(a)     Restated Certificate of Incorporation of MDU Resources, as
                    amended, filed as Exhibit 3(a) to Form 10-Q for the quarter
                    ended June 30, 2002, in File No. 1-3480.

          *3(b)     Certificate of Designations of Series B Preference Stock of
                    MDU Resources, as amended, filed as Exhibit 3(a) to Form
                    10-Q for the quarter ended September 30, 2002, in File No.
                    1-3480.

           3(c)     Bylaws of MDU Resources, as amended.

          *4(a)     Indenture of Mortgage, dated as of May 1, 1939, as restated
                    in the Forty-Fifth Supplemental Indenture, dated as of April
                    21, 1992, and the Forty-Sixth through Forty-Ninth
                    Supplements thereto between MDU Resources and The New York
                    Trust Company (The Bank of New York, successor Corporate
                    Trustee) and A. C. Downing (Douglas J. MacInnes, successor
                    Co-Trustee), filed as Exhibit 4(a) in Registration No.
                    33-66682; Exhibits 4(e), 4(f) and 4(g) in Registration No.
                    33-53896; and Exhibit 4(c)(i) in Registration No. 333-49472.

          *4(b)     Rights Agreement, dated as of November 12, 1998, between
                    MDU Resources and Wells Fargo Bank Minnesota, N.A. (formerly
                    known as Norwest Bank Minnesota, N.A.), Rights Agent, filed
                    as Exhibit 4.1 to Form 8-A on November 12, 1998, in File No.
                    1-3480.

           5(a)     Opinion of Lester H. Loble, II, Esq., General Counsel to MDU
                    Resources.

           5(b)     Opinion of LeBoeuf, Lamb, Greene & MacRae, L.L.P., counsel
                    to MDU Resources.

           8        Opinion of LeBoeuf, Lamb, Greene & MacRae, L.L.P., counsel
                    to MDU Resources (included in Exhibit 5(b)).

          23(a)     Consent of Deloitte & Touche LLP, independent public
                    accountants.

          23(b)     Consents of Lester H. Loble, II, Esq. and LeBoeuf, Lamb,
                    Greene & MacRae, L.L.P. (included in their opinions filed as
                    Exhibit 5(a) and Exhibit 5(b), respectively).

          24        Power of Attorney (included as part of the signature pages).

-------------------
* Incorporated herein by reference as indicated.

Arthur Andersen LLP has not consented to the incorporation by reference of their
audit report, dated January 23, 2002, in this Post-Effective Amendment No. 1 to
Registration Statement on


                                      II-1




Form S-3 (No. 333-06127), and we have dispensed with the requirement to file
their consent in reliance on Rule 437a under the Securities Act of 1933, as
amended.


                                      II-2




ITEM 17. UNDERTAKINGS.

     (a)  The undersigned registrant hereby undertakes:

          (1)  To file, during any period in which offers or sales are being
               made, a post-effective amendment to this registration statement:

               (i)  To include any prospectus required by Section 10(a)(3) of
                    the Securities Act of 1933;

               (ii) To reflect in the prospectus any facts or events arising
                    after the effective date of the registration statement (or
                    the most recent post-effective amendment thereof) which,
                    individually or in the aggregate, represent a fundamental
                    change in the information set forth in the registration
                    statement. Notwithstanding the foregoing, any increase or
                    decrease in volume of securities offered (if the total
                    dollar value of securities offered would not exceed that
                    which was registered) and any deviation from the low or high
                    end of the estimated maximum offering range may be reflected
                    in the form of prospectus filed with the Commission pursuant
                    to Rule 424(b) if, in the aggregate, the changes in volume
                    and price represent no more than 20 percent change in the
                    maximum aggregate offering price set forth in the
                    "Calculation of Registration Fee" table in the effective
                    registration statement; and

               (iii) To include any material information with respect to the
                    plan of distribution not previously disclosed in the
                    registration statement or any material change to such
                    information in the registration statement;

               provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) do
               not apply if the registration statement is on Form S-3, Form S-8
               or Form F-3 and the information required to be included in a
               post-effective amendment by those paragraphs is contained in
               periodic reports filed with or furnished to the Commission by the
               registrant pursuant to Section 13 or Section 15(d) of the
               Securities Exchange Act of 1934 that are incorporated by
               reference in the registration statement.

          (2)  That, for the purpose of determining any liability under the
               Securities Act of 1933, each such post-effective amendment shall
               be deemed to be a new registration statement relating to the
               securities offered therein, and the offering of such securities
               at that time shall be deemed to be the initial bona fide offering
               thereof.

          (3)  To remove from registration by means of a post-effective
               amendment any of the securities being registered which remain
               unsold at the termination of the offering.


                                      II-3




     (b)  The undersigned registrant hereby undertakes that, for purposes of
          determining any liability under the Securities Act of 1933, each
          filing of the registrant's annual report pursuant to Section 13(a) or
          15(d) of the Securities Exchange Act of 1934 (and, where applicable,
          each filing of an employee benefit plan's annual report pursuant to
          Section 15(d) of the Securities Exchange Act of 1934) that is
          incorporated by reference in the registration statement shall be
          deemed to be a new registration statement relating to the securities
          offered therein, and the offering of such securities at that time
          shall be deemed to be the initial bona fide offering thereof.

     Insofar as indemnification for liabilities arising under the Securities Act
of 1933 may be permitted to directors, officers and controlling persons of the
registrant pursuant to the provisions described under Item 15 above, or
otherwise, the registrant has been advised that in the opinion of the Securities
and Exchange Commission such indemnification is against public policy as
expressed in the Securities Act of 1933 and is, therefore, unenforceable. In the
event that a claim for indemnification against such liabilities (other than the
payment by the registrant of expenses incurred or paid by a director, officer or
controlling person of the registrant in the successful defense of any action,
suit or proceeding) is asserted by such director, officer or controlling person
in connection with the securities being registered, the registrant will, unless
in the opinion of its counsel the matter has been settled by controlling
precedent, submit to a court of appropriate jurisdiction the question whether
such indemnification by it is against public policy as expressed in the
Securities Act of 1933, and will be governed by the final adjudication of such
issue.


                                      II-4




                                   SIGNATURES

     Pursuant to the requirements of the Securities Act of 1933, the registrant
certifies that it has reasonable grounds to believe that it meets all of the
requirements for filing on Form S-3 and has duly caused this Post-Effective
Amendment No. 1 to the Registration Statement on Form S-3 to be signed on its
behalf by the undersigned, thereunto duly authorized, in the City of Bismarck,
State of North Dakota on the 7th day of March, 2003.

                                         MDU RESOURCES GROUP, INC.

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

                                POWER OF ATTORNEY

     Each director and/or officer of the registrant whose signature appears
below hereby appoints the Agents for Service named on the cover of this
Post-Effective Amendment No. 1 to the Registration Statement on Form S-3, and
each of them severally, as his/her attorney-in-fact to sign in his/her name and
behalf, in any and all capacities stated below, and to file with the Securities
and Exchange Commission, any and all amendments, including post-effective
amendments, to the Registration Statement, and the registrant hereby also
appoints each such Agent for Service as its attorney-in-fact with like authority
to sign and file any such amendment in its name and behalf.

     Pursuant to the requirements of the Securities Act of 1933, this
Post-Effective Amendment No. 1 to the Registration Statement on Form S-3 has
been signed by the following persons in the capacities and on the dates
indicated.



                      Signature                                  Title                            Date

                                                                                     
/s/ Martin A. White                                     Chief Executive Officer               March 7, 2003
--------------------------------------------            and Director
Martin A. White
(Chairman of the Board, President
and Chief Executive Officer)

/s/ Warren L. Robinson                                  Chief Financial Officer               March 7, 2003
--------------------------------------------
Warren L. Robinson
(Executive Vice President, Treasurer
and Chief Financial Officer)

/s/ Vernon A. Raile                                     Chief Accounting Officer              March 7, 2003
--------------------------------------------
Vernon A. Raile
(Senior Vice President, Controller
and Chief Accounting Officer)


                                      II-5




/s/ Harry J. Pearce                                     Lead Director                         March 7, 2003
--------------------------------------------
Harry J. Pearce

                                                        Director
--------------------------------------------
Bruce R. Albertson

/s/ Thomas Everist                                      Director                              March 7, 2003
--------------------------------------------
Thomas Everist

/s/ Dennis W. Johnson                                   Director                              March 7, 2003
--------------------------------------------
Dennis W. Johnson

/s/ Robert L. Nance                                     Director                              March 7, 2003
--------------------------------------------
Robert L. Nance

/s/ John L. Olson                                       Director                              March 7, 2003
--------------------------------------------
John L. Olson

/s/ Homer A. Scott, Jr.                                 Director                              March 7, 2003
--------------------------------------------
Homer A. Scott, Jr.

/s/ Joseph T. Simmons                                   Director                              March 7, 2003
--------------------------------------------
Joseph T. Simmons

/s/ Sister Thomas Welder                                Director                              March 7, 2003
--------------------------------------------
Sister Thomas Welder



                                      II-6




                                  EXHIBIT INDEX

       Exhibit No.          Description

          *3(a)     Restated Certificate of Incorporation of MDU Resources, as
                    amended, filed as Exhibit 3(a) to Form 10-Q for the quarter
                    ended June 30, 2002, in File No. 1-3480.

          *3(b)     Certificate of Designations of Series B Preference Stock of
                    MDU Resources, as amended, filed as Exhibit 3(a) to Form
                    10-Q for the quarter ended September 30, 2002, in File No.
                    1-3480.

           3(c)     Bylaws of MDU Resources, as amended.

          *4(a)     Indenture of Mortgage, dated as of May 1, 1939, as restated
                    in the Forty-Fifth Supplemental Indenture, dated as of April
                    21, 1992, and the Forty-Sixth through Forty-Ninth
                    Supplements thereto between MDU Resources and The New York
                    Trust Company (The Bank of New York, successor Corporate
                    Trustee) and A. C. Downing (Douglas J. MacInnes, successor
                    Co-Trustee), filed as Exhibit 4(a) in Registration No.
                    33-66682; Exhibits 4(e), 4(f) and 4(g) in Registration No.
                    33-53896; and Exhibit 4(c)(i) in Registration No. 333-49472.

          *4(b)     Rights Agreement, dated as of November 12, 1998, between
                    MDU Resources and Wells Fargo Bank Minnesota, N.A. (formerly
                    known as Norwest Bank Minnesota, N.A.), Rights Agent, filed
                    as Exhibit 4.1 to Form 8-A on November 12, 1998, in File No.
                    1-3480.

           5(a)     Opinion of Lester H. Loble, II, Esq., General Counsel to MDU
                    Resources.

           5(b)     Opinion of LeBoeuf, Lamb, Greene & MacRae, L.L.P., counsel
                    to MDU Resources.

           8        Opinion of LeBoeuf, Lamb, Greene & MacRae, L.L.P., counsel
                    to MDU Resources (included in Exhibit 5(b)).

          23(a)     Consent of Deloitte & Touche LLP, independent public
                    accountants.

          23(b)     Consents of Lester H. Loble, II, Esq. and LeBoeuf, Lamb,
                    Greene & MacRae, L.L.P. (included in their opinions filed as
                    Exhibit 5(a) and Exhibit 5(b), respectively).

          24        Power of Attorney (included as part of the signature pages).

-------------------
* Incorporated herein by reference as indicated.

Arthur Andersen LLP has not consented to the incorporation by reference of their
audit report, dated January 23, 2002, in this Post-Effective Amendment No. 1 to
Registration Statement on Form S-3 (No. 333-06127), and we have dispensed with
the requirement to file their consent in reliance on Rule 437a under the
Securities Act of 1933, as amended.