MDU RESOURCES GROUP, INC.

                SUPPLEMENTAL INCOME SECURITY PLAN

    (As Amended and Restated Effective as of January 1, 2005)




                        TABLE OF CONTENTS



INTRODUCTION

ARTICLE I -- DEFINITIONS

ARTICLE II -- ELIGIBILITY

ARTICLE III -- SUPPLEMENTAL DEATH AND RETIREMENT BENEFITS

ARTICLE IV -- EXCESS RETIREMENT BENEFITS

ARTICLE V -- DISABILITY BENEFITS

ARTICLE VI -- MISCELLANEOUS

ARTICLE VII -- ADDITIONAL AFFILIATED COMPANIES

APPENDIX A - SCHEDULE OF RETIREMENT AND SURVIVORS BENEFITS

APPENDIX B - CURRENT PARTICIPANTS ELIGIBLE FOR ARTICLE IV BENEFITS



                          INTRODUCTION

     The objective of the MDU Resources Group, Inc.
Supplemental Income Security Plan (the "Plan") is to provide
certain levels of survivor benefits and retirement income for a
select group of management or highly compensated employees and
their families.  Eligibility for participation in this Plan shall
be limited to management or highly compensated employees who are
selected by the Chief Executive Officer of MDU Resources Group,
Inc. (the "Company").  This Plan became effective January 1,
1982, has been amended from time to time thereafter, and most
recently has been amended and restated effective as of January 1,
2005.
     The Plan is intended to constitute an unfunded "excess
benefit plan" as defined in Section 3(36) of the Employee
Retirement Income Security Act of 1974, as amended ("ERISA"), to
the extent it provides benefits that would be paid under one or
more of the tax-qualified retirement plans of the Company or
certain of its subsidiaries but for certain limitations set forth
under the Internal Revenue Code of 1986, as amended (the "Code"),
and constitutes an unfunded plan of deferred compensation
maintained by the Company primarily for the purpose of provided
non-elective deferred compensation for a select group of
management or highly compensated employees.

                    ARTICLE I -- DEFINITIONS

     Unless a different meaning is plainly implied by the
context, the following terms as used in this Plan shall have the
following meanings:
     1.1  "Administrator" means the Chief Executive Officer of the
Company or any other person to whom the Chief Executive Officer
of the Company has delegated the authority to administer the
Plan.  The Vice President - Human Resources of the Company is
initially delegated the authority to perform the administrative
responsibilities required under the Plan.
     1.2  "Affiliated Company" means any current or future corporation
which (a) is in a controlled group of corporations (within the
meaning of Section 414(b) of the Code) of which the Company is a
member and (b) has been approved by the Chief Executive Officer
of the Company to adopt the Plan for the benefit of its
Employees.
     1.3  "Beneficiary" means an individual or individuals, any entity
or entities (including corporations, partnerships, estates or
trusts) that shall be entitled to receive benefits payable
pursuant to the provisions of this Plan by virtue of a
Participant's death; provided, however, that if more than one
such person is designated as a Beneficiary hereunder, each such
person's proportionate share of the death benefit hereunder must
clearly be set forth in a written statement of the Participant
received by and filed with the Administrator prior to the
Participant's death.  If such proportionate share for each
Beneficiary is not set forth in the designation, each Beneficiary
shall receive an equal share of the death benefits provided
hereunder.
     1.4  "Company" means MDU Resources Group, Inc., and its
successors, if any.
     1.5  "Effective Date" of the Plan means January 1, 1982.  The
Effective Date of this amendment and restatement of the Plan is
January 1, 2005.
     1.6  "Eligible Retirement Date" means the First Eligible
Retirement Date and the last day of each subsequent calendar
month.
     1.7  "Employee" means each person actively employed by an
Employer, as determined by such Employer in accordance with its
practices and procedures.
     1.8  "Employer" means the Company and any Affiliated Company
which shall adopt this Plan with respect to its Employees with
the prior approval of the Company as set forth in Article 7 of
the Plan.
     1.9  "First Eligible Retirement Date" for a Participant means the
last day of the month during which such Participant is both no
longer actively employed by any Employer and has attained at
least age 65.
     1.10 "Limitation on Benefits" shall mean the statutory limitation
on the maximum benefit that may be payable to participants under
a Pension Plan due to the application of certain provisions
contained in the Code.
     1.11 "Participant" means a present or former management or highly
compensated Employee selected by the Chief Executive Officer of
the Company to receive benefits under this Plan.  An Employee
will become a Participant at the time such Employee commences
participation hereunder pursuant to the provisions of Section 2.1
hereof.
     1.12 "Pension Plan" means the MDU Resources Group, Inc. Pension
Plan for Non-Bargaining Unit Employees, the Williston Basin
Interstate Pipeline Company Pension Plan, or the Knife River
Corporation Salaried Employees' Pension Plan, as in effect on the
Effective Date and as amended from time to time.
     1.13 "Plan" means the MDU Resources Group, Inc. Supplemental
Income Security Plan, as embodied herein, and any amendments
thereto.
     1.14 "Plan Year" means the calendar year.  The first Plan Year
for this Plan shall be the 1982 calendar year.
     1.15 "Salary" means annual base earnings payable by an Employer
to a Participant excluding (a) bonuses, (b) incentive
compensation, and (c) any other form of supplemental income.
     1.16 "Standard Actuarial Factors" means, with respect to a
Participant, the actuarial factors and assumptions commonly used
for the calculation of actuarial equivalents for retirement plans
as determined by the Administrator.
     1.17 "Standard Life Insurance" means life insurance that could be
purchased from a commercial life insurance company at standard
rates without a surcharge assessed, based on an individual's
general good health.
     1.18 "Standard Underwriting Factors" means life insurance rating
factors utilized by a commercial life insurance company selected
by the Chief Executive Officer of the Company which are based on
the risk assessment classifications utilized by such insurer to
determine if an applicant qualifies for insurance at standard
rates or if health or other factors might require a surcharge.
     1.19 "Year of Participation" means each 12 consecutive months of
participation in the Plan by a Participant while actively
employed by one or more of the Employers (including while such
Participant is qualified as totally disabled as defined in
Article V), as determined at the sole discretion of the
Administrator.

                    ARTICLE II -- ELIGIBILITY

     2.1  Eligibility for Participation.  The Chief Executive Officer
of the Company in his or her complete discretion shall determine
which management or highly compensated Employees may be eligible
to participate in the Plan.  Effective after January 1, 2005,
general criteria for initial consideration of an Employee
include, but  are not limited to, the following:  (a) either an
officer or a management employee of an Employer earning an annual
base salary  of $150,000 or more, indexed in a manner described
below;  (b) an executive who makes a significant contribution to
the Company's success and profitability; and (c) an executive in
a business unit where benefits of this nature are a common
practice, or there is a specific need to recruit and retain key
executives.  Each Employee who is selected as eligible to
participate hereunder and who meets the requirements for
participation set forth under Section 2.2 hereof shall commence
participation of the first day of the month coincident with or
next following the date of such Employee's selection.  The annual
base salary threshold of $150,000 will be indexed each year after
2005 by the Administrator according to the average salary growth
assumptions used in the Pension Plans, or other appropriate
executive salary growth reference.  In addition to the annual
indexing, the Administrator will, from time to time, compare the
annual base salary threshold to competitive practice and
recommend adjustments accordingly to the Chief Executive Officer.
     2.2  Requirements for Participation.  In order to be eligible to
participate in the Plan, an Employee selected by the Chief
Executive Officer of the Company must (a) be actively at work for
one or more of the Employers; (b) have a current state of health
and physical condition that would satisfy customary requirements
for insurability under Standard Life Insurance; provided,
however, that no provision of this Plan shall be construed or
interpreted to limit participation in the Plan in contravention
of the Americans With Disabilities Act and related federal and
state laws; and (c) consent to supply information or to otherwise
cooperate as necessary to allow the Company to obtain life
insurance on behalf of such Employee (as set forth under Section
6.3 of the Plan).
     2.3  Eligibility for Benefits.  Subject to the provisions of
Article III, Plan benefits may commence as of the earlier to
occur of (a) the first day of the month following the date of the
Participant's death or (b) if the Participant who elects to
receive retirement benefits under Article III hereof, the
Participant's First Eligible Retirement Date, for purposes of the
benefits payable under Article III of the Plan.
     2.4  Relationship to Other Plans.  Participation in the Plan
shall not preclude or limit the participation of the Participant
in any other benefit plan sponsored by one or more of the
Employers for which such Participant otherwise would be eligible.
However, any benefits payable under this Plan shall not be deemed
salary or compensation to the Participant for purposes of
determining benefits under any other employee benefit plan
maintained by one or more of the Employers.
     2.5  Forfeiture of Benefits.  Notwithstanding any provision of
this Plan to the contrary, if any Participant is discharged from
employment by one or more of the Employers for cause due to
willful misconduct, dishonesty, or conviction of a crime or
felony, all as determined at the sole discretion of the Chief
Executive Officer of the Company, the rights of such Participant
(or any Beneficiary of such Participant) to any present or future
benefit under this Plan shall be forfeited to the extent not
prohibited by applicable law.

    ARTICLE III -- SUPPLEMENTAL DEATH AND RETIREMENT BENEFITS

     3.1  Amount of Benefit.  (a)  Subject to the provisions of
Section 3.3 of the Plan, the monthly supplemental death and/or
retirement benefits payable on behalf of (or to) a Participant as
of such Participant's date of death (or First Eligible Retirement
Date) will be an amount determined at the sole discretion of the
Chief Executive Officer of the Company at the time of the
Participant's commencement of participation in the Plan, as may
be adjusted from time to time thereafter by the Chief Executive
Officer of the Company.  However, in no event will a Participant
be entitled to have a monthly supplemental death benefit paid on
such Participant's behalf (or be entitled to receive a monthly
supplemental retirement benefit) that exceeds the monthly death
benefit or monthly retirement benefit (as applicable)
corresponding to the Participant's Salary in effect at the date
such initial or revised benefit determination is to be effective,
all as set forth in the applicable Appendix A hereto.  Benefits
for Participants shall be determined in accordance with Appendix A.
Changes in Salary do not automatically result in changes to a
Participant's level of benefits.  Without limiting the scope of
the immediately preceding sentence, it is intended that
adjustments to a Participant's benefit level after commencement
of participation in the Plan will be made only to the extent the
Participant's current compensation exceeds the then current
annual base salary threshold determined pursuant to Section 2.1
as a general criterion for eligibility.
     (b)  Participants who died, terminated employment with, or
retired from, the Employers prior to January 1, 2002, will
receive benefits hereunder in accordance with the terms of the
Plan as in effect at the time of the Participant's death,
termination of employment or retirement from the Employers.
     (c)  The benefit amounts determined by the Chief Executive
Officer of the Company pursuant to Section 3.1(a) above are based
on the assumption that each Participant's health and physical
condition at the time of such Participant's commencement of
participation in the Plan meets customary requirements for
Standard Life Insurance.  Benefits under the Plan may be reduced
by the Chief Executive Officer of the Company within a reasonable
period following the establishment of such benefit level in
accordance with Standard Underwriting Factors, but only with
respect to that portion of the monthly death or retirement
benefit for which the criteria for health and physical condition
are not met.  Participants will be notified of any such reduction
within a reasonable period following participation in the Plan.
Once benefits have been reduced under this Section 3.1, such
benefits shall not be further reduced for the remainder of the
Participant's participation in the Plan.
     (d)  Participants who die while actively employed will be
considered to be 100% vested for the death benefit, and not
subject to the vesting schedule.  However, once the participant
is no longer actively employed (e.g. resignation, termination,
disability, etc.) Section 3.2 applies.
     3.2  Vesting.  If a Participant retires or terminates employment
with an Employer before the Participant completes at least 10
years of Participation, the monthly death and/or retirement
benefits to which such Participant otherwise would be entitled
under the terms of Section 3.1 hereof shall vest as follows:

                               Vesting Schedule
           Years of Participation                Percent of Section
        Completed by the Participant            3.1 Benefits Payable

                     1                                   0%
                     2                                   0%
                     3                                  20%
                     4                                  40%
                     5                                  50%
                     6                                  60%
                     7                                  70%
                     8                                  80%
                     9                                  90%
                    10                                 100%


     3.3  Payment of Monthly Benefit.  Upon attainment of age 65 or,
as of such Participant's First Eligible Retirement Date (if
later), a Participant will be entitled to determine the form of
benefit payable under subsection (a) hereof, and the date of
commencement of such benefits, subject to the approval of the
Chief Executive Officer of the Company, in accordance with the
terms of the Plan.  The Participant may elect:
     (a) to defer any payments and retain a future monthly
death benefit in amounts determined pursuant to Section 3.1
hereof, multiplied by the appropriate percentage amount set forth
in section 3.2, or
     (b) in lieu of any death benefits under this Plan a
monthly retirement benefit determined in accordance with Section
3.1, multiplied by the appropriate percentage amount set forth in
Section 3.2, with no death benefit, or
     (c) a percentage of each benefit described in subsections
(a and b) above.  The percentage of each benefit must be in even
increments of ten percent (10%).
               (i) If a Participant has elected to receive less
               than one hundred percent (100%) of such
               Participant's monthly retirement benefit (e.g.
               50%), the Participant may subsequently elect to
               begin receiving an additional percentage
               retirement benefit (e.g. another 20%.) There may
               be no more than two (2) such additions during the
               Participant's lifetime, and no more than one (1)
               such addition during any calendar year.
               (ii) Any such addition in retirement benefit
               payments will result in an equal percentage
               reduction in death benefits, to the percentage
               change in retirement benefit.
               (iii) Once retirement benefit payments have
               started, Participants shall not be entitled to
               subsequently decrease retirement benefit payments.
     (d) Elections under this Section 3.3 must be
communicated in writing to the Administrator and will be
effective as of the first day of the first month following
the Administrator's receipt and the approval of such request
by the Chief Executive Officer of the Company.
     3.4  Payment of Monthly Benefits.  (a)  Death Benefits.  Any
death benefits payable with respect to a Participant pursuant to
Sections 3.3(a)(b) or (c) shall commence on the first day of the
calendar month following the date of the Participant's death and
shall be payable in monthly installments for a period of 180
months.
     (b)  Retirement Benefits.  The monthly retirement benefits
payable under this Plan shall commence on the Eligible Retirement
Date selected by the Participant (upon 30 day's written notice to
the Administrator) and will be payable to such Participant in
monthly installments for a period of 180 months.  In the event
the Participant dies prior to the completion of such 180-month
period, the balance of such retirement benefits shall be paid to
the Participant's Beneficiary at such times and in such amounts
as if the Participant had not died, such payment being made in
addition to any death benefits payable under Sections 3.3(a)(i)
or (iii) hereof.  To the extent a Participant elects to commence
receiving increased retirement benefits pursuant to Section
3.3(b), the amount of increase of retirement benefits shall be in
the form of a monthly benefit payable for a separate 180-month
period.
     (c)  Actuarial Equivalent Alternative Forms.  The normal form of
retirement benefit to which a Participant shall be entitled shall
be determined under paragraph 3.4(b).  Alternatively, a
participant may elect to receive their Retirement Benefit in one
of the following actuarially equivalent forms (as determined by
the Administrator), provided however that each alternative form
shall also be payable for a certain period of 180 months:  (i)
The lifetime of the Participant; (ii) The lifetime of the
Participant with the same amount payable to the Participant
continued thereafter for the lifetime of the Participant's
spouse; or (iii) The lifetime of the Participant with 67% of the
amount payable to the Participant continued thereafter for the
lifetime of the Participant's spouse.  However, in no event will
the Company incur more costs in providing the actuarial
equivalent alternative form to the Participant than it would
otherwise incur in providing the normal form of retirement
benefit.  Applying the discount rate used by the Company to
calculate the FAS 87 expense, the present value of the
Participant's retirement benefit will be calculated by the
Administrator.  The Administrator will then purchase an annuity
at a cost no greater than the present value of the retirement
benefit.
     (d)  Single Sum Payment.  Notwithstanding the provisions of
subsections (a) and (b) of this Section 3.4, the Chief Executive
Officer of the Company reserves the right to pay benefits in the
form of an actuarially equivalent single sum (as determined by
the Administrator) when retirement or death benefits are payable
due to termination of employment, excluding disability, or death
prior to the Participant's attainment of age 55, or upon the
death of the Participant and the primary beneficiary(ies).
     3.5  Exclusions and Limitations.  (a) No death benefits will be
payable with respect to a Participant in the event of such
Participant's death by suicide within two (2) years after
commencement of participation in the Plan, and no benefit
increase will apply in the event of any such Participant's death
by suicide within two (2) years after such Participant becomes
eligible for an increase in death benefits.
     (b)  In the event that a Participant misrepresents any health or
physical condition at the time of commencement of participation
in the Plan or at the time of a retirement or death benefit
increase, no retirement or death benefit or retirement or death
benefit increase will be payable under the Plan within two (2)
years of such misrepresentation.
     3.6  Death of a Beneficiary.  (a)  In the event any Beneficiary
predeceases the Participant, is not in existence, is not
ascertainable, or is not locatable (see Section 6.11) as of the
date benefits under the Plan become payable to such Beneficiary,
Plan benefits shall be paid to such contingent Beneficiary or
Beneficiaries as shall have been named by the Participant on the
Participant's most recent Beneficiary election form that has been
received and filed with the Administrator prior to the
Participant's death.  If no contingent Beneficiary has been
named, the contingent Beneficiary shall be the Participant's
estate.
     (b)  In the event any Beneficiary dies after commencing to
receive monthly benefits under the Plan but prior to the payment
of all monthly benefits to which such Beneficiary is entitled,
remaining benefits shall be paid to a beneficiary designated by
the deceased Beneficiary (the "Secondary Beneficiary"), provided
such designation has been received and filed with the
Administrator prior to the death of the Beneficiary.  If no such
person has been designated by the deceased Beneficiary, the
Secondary Beneficiary shall be the estate of the Beneficiary.  In
the event the Secondary Beneficiary shall die prior to the
payment of all benefits to which such Secondary Beneficiary is
entitled, the remainder of such payments shall be made to such
Secondary Beneficiary's estate.  If the Administrator is in doubt
as to the right of any person to receive benefits under the Plan,
the Administrator may retain such amount, without liability for
any interest thereon, until the rights thereto are determined, or
the Administrator may pay a single sum amount in accordance with
Section 3.4 (c) into any court of competent jurisdiction and such
payment shall be a complete discharge of the liability of the
Plan and the Employer therefor.
     3.7  Discretion As To Benefit Amount.  Notwithstanding the
foregoing, the Chief Executive Officer of the Company may, with
full and complete discretion, disregard Standard Underwriting
Factors and customary requirements for Standard Life Insurance in
establishing and/or increasing the amount of any Participant's
retirement or death benefit under the Plan.
3.8  Suspension of Benefits Upon Reemployment.  Employment with
any Employer subsequent to the commencement of retirement
benefits under this Article III may, at the sole discretion of
the Chief Executive Officer of the Company, result in the
suspension of such benefits for the period of such employment or
reemployment.

         ARTICLE IV --  REPLACEMENT RETIREMENT BENEFITS

     4.1  Participation.  Benefits under this Article IV shall be
payable only to those Participants whose benefits, under a
Pension Plan under which they otherwise participate, are reduced
or limited by reason of the Limitation on Benefits.  Except for
those Participants listed on Appendix B, benefits under Article
IV are limited to Participants who retire or terminate from the
Employer no earlier than the age at which there is no Pension
Plan benefit reduction due to early retirement.  Participants
listed on Appendix B shall be eligible to receive benefits under
Article IV if they begin receiving benefits under a Pension Plan
at any time prior to age 65.  Benefits under this Article IV (a)
shall be payable only for such period that the benefits under the
Pension Plan are actually reduced or limited and (b) shall
terminate as of the last day of the month immediately preceding
the month during which occurs the Participant's sixty-fifth
(65th) birthday.  Furthermore, benefits under this Article IV
also shall be payable only to those Participants who are active
Employees on or after January 1, 1997.
      4.2  Amount and Method of Payment.  (a)  Amount of Benefit.  The
amount, if any, of the monthly benefit payable to or on account
of a Participant pursuant to this Article IV shall equal the
difference of (i) minus (ii) where:
           (i)  equals the amount of monthly retirement benefits which
                would be provided to the Participant under the Pension Plan
                without regard to the Limitation of Benefits; and
           (ii) equals the amount of monthly retirement benefits payable
                to such Participant under the Pension Plan due to the
                application of the Limitation on Benefits;
provided, however, that no benefits shall be payable to a
Participant under this Article IV unless the amount of such
monthly benefit is at least fifty dollars ($50).  The benefit
amount provided under this Section 4.2(a) shall be determined
with reference to the form of benefit determined under section
4.2(c) hereof and shall be calculated in accordance with the
Standard Actuarial Factors utilized under the Pension Plan.
     (b)  Vesting.  A Participant shall be vested in benefits under
this Article IV to the same extent as such Participant is vested
in benefits under the applicable Pension Plan.
     (c)  Payment of Benefit.  The benefits provided under this
Article IV shall be paid to each such Participant, surviving
spouse (as defined under the applicable Pension Plan) or joint
annuitant (as defined under the applicable Pension Plan) at the
same time and in the same form and manner as benefits are payable
under the applicable Pension Plan.  Payments shall be made in
accordance with, and subject to, the terms and conditions of the
applicable Pension Plan; provided, however, that no spousal
consent shall be required to commence any form of payment under
this Article IV.
     (d)  Duration of Payments.  Subject to Section 4.2(c), benefits
provided under this Article IV shall commence at the same time as
payments commence under the applicable Pension Plan, and shall
continue to age 65 or the death of the Participant, if prior to
age 65, and, if applicable, in reduced amount until the death of
the Participant's spouse or joint annuitant, whichever is
applicable.
     (e)  Treatment During Subsequent Employment.  Employment with any
Employer subsequent to the commencement of benefits under this
Article IV may, at the sole discretion of the Chief Executive
Office of the Company, result in the suspension of such benefits
for the period of such employment or reemployment to the extent
set forth under the applicable Pension Plan.
     (f)  Necessity of Actual Reduction.  Notwithstanding any other
provision of this Plan, no amount shall be payable under this
Article IV unless the Participant's monthly benefit paid under
the applicable Pension Plan is actually reduced because of
application of the Limitation on Benefits.  Benefits payable to a
Participant under this Article IV shall not duplicate benefits
payable to such Participant from any other plan or arrangement of
the Company.  In the event a change in law or regulation
liberalizes the limitations applicable to determining the
Limitation on Benefits such that a Participant may receive
additional benefits under the applicable Pension Plan, and the
applicable Pension Plan provides for the payment of such
additional benefits to the Participant, the amount payable under
this Article IV shall be reduced by a corresponding amount.

                ARTICLE V -- DISABILITY BENEFITS

     5.1  Monthly Disability Benefit.  (a)  If a Participant becomes
totally disabled following commencement of participation in the
Plan, the Participant shall continue to receive credit for up to
2 years of Participation under the Plan for so long as the
Participant is totally disabled. Following termination of the
participant's employment with the Employer, the Participant's
monthly retirement benefits under Article III of the Plan shall
commence beginning on or after the Participant's First Eligible
Retirement Date.
     (b)  A Participant is "totally disabled" if such Participant is
disabled within the meaning of the applicable long-term
disability plan sponsored by such Participant's Employer, or as
determined by Social Security.
     (c)  If a Participant who is totally disabled dies before
attaining age 65, any death benefit payable to the Participant's
Beneficiary will be determined and paid in accordance with the
vesting schedule terms of Article III.

                   ARTICLE VI - MISCELLANEOUS

     6.1  Amendment and Termination.  Any action to amend, modify,
suspend or terminate the Plan may be taken at any time, and from
time to time, by resolution of the Board of Directors of the
Company (or any person or persons duly authorized by resolution
of the Board of Directors of the Company to take such action) in
its sole discretion and without the consent of any Participant or
Beneficiary, but no such action shall retroactively reduce any
benefits accrued by any Participant under this Plan prior to the
time of such action.
     6.2  No Guarantee of Employment.  Nothing contained herein shall
be construed as a contract of employment between a Participant
and any Employer or shall be deemed to give any Participant the
right to be retained in the employ of any Employer.
     6.3  Funding of Plan and Benefit Payments.  This Plan is unfunded
within the meaning of ERISA.  Each Employer will make Plan
benefit payments from its general assets.  Each Employer may
purchase policies of life insurance on the lives of Plan
Participants and to refuse participation in the Plan to any
Employee who, if requested to do so, declines to supply
information or to otherwise cooperate so that the Employer may
obtain life insurance on behalf of such Participant.  The
Employer will be the owner and the beneficiary of any such
policy, and Plan benefits will be neither limited to nor secured
by any such policy or its proceeds.  Participants and their
Beneficiaries shall have no right, title or interest in any such
life insurance policies, in any other assets of any Employer or
in any investments any Employer may make to assist it in meeting
its obligations under the Plan.  All such assets shall be solely
the property of such Employer and shall be subject to the claims
of such Employer's general creditors.  There are no assets of any
Employer that are identified or segregated for purposes of the
payment of any benefits under this Plan.  To the extent a
Participant or any other person acquires a right to receive
payments from an Employer under the Plan, such right shall be no
greater than the right of any unsecured general creditor of such
Employer and such person shall have only the unsecured promise of
the Employer that such payments shall be made.
     6.4  Payment Not Assignable.  Except in the case of a Qualified
Domestic Relations Order described under Code Section 414(p),
Participants and their Beneficiaries shall not have the right to
alienate, anticipate, commute, sell, assign, transfer, pledge,
encumber or otherwise convey the right to receive any payments
under the Plan, and any payments under the Plan or rights thereto
shall not be subject to the debts, liabilities, contracts,
engagements or torts of Participants or their Beneficiaries nor
to attachment, garnishment or execution, nor shall they be
transferable by operation of law in the event of bankruptcy or
insolvency.  Any attempt, whether voluntary or involuntary, to
effect any such action shall be null, void and of no effect.
     6.5  Applicable Law.  The Plan and all rights hereunder shall be
governed by and construed according to the laws of the State of
Delaware, except to the extent such laws are preempted by the
laws of the United States of America.
     6.6  Claims Procedure.  (a)  Participants and Beneficiaries
eligible for benefits under the Plan, or any person duly
authorized by them, have the right under ERISA and the Plan to
file a written claim to the Administrator for payment of such
benefits.
     (b)  If the claim is denied in whole or in part, the claimant
will receive written notice of the Administrator's decision,
including the specific reason for the decision, within 90 days
after the Administrator received the claim.  If the Administrator
needs more than 90 days to make a decision, the Administrator
will notify the individual in writing within the initial 90-day
period.  An additional 90 days may be taken if the Administrator
sends this notice.  The extension notice will show the date by
when the Administrator's decision will be sent.
     6.7  Plan Administration.  (a)  The Plan shall be administered by
the Administrator.  The Administrator shall serve as the final
review under the Plan and shall have sole and complete
discretionary authority to determine conclusively for all
persons, and in accordance with the terms of the documents or
instruments governing the Plan, any and all questions arising
from the administration of the Plan and interpretation of all
Plan provisions.  The Administrator shall make the final
determination of all questions relating to participation of
employees and eligibility for benefits, and the amount and type
of benefits payable to any Participant or Beneficiary.  In no way
limiting the foregoing, the Administrator shall have the
following specific duties and obligations in connection with the
administration of the Plan:
          (i) To promulgate and enforce such rules, regulations and
              procedures as may be proper for the efficient administration
              of the Plan;
         (ii) To determine all questions arising in the administration,
              interpretation and application of the Plan, including
              questions of eligibility and of the status and rights of
              Participants and any other persons hereunder;
        (iii) To decide any dispute arising hereunder; provided,
              however, that the Administrator shall not participate in any
              matter involving any questions relating solely to the
              Administrator's own participation or benefit under this Plan;
         (iv) To advise the Boards of Directors of the Employers regarding
              the known future need for funds to be available for distribution;
          (v) To advise the Boards of Directors of the Employers regarding
              the known future need for funds to be available for distribution;
         (vi) To compute the amount of benefits and other payments which
              shall be payable to any Participant or Beneficiary in accordance
              with the provisions of the Plan and to determine the person or
              persons to whom such benefits shall be paid;
        (vii) To make recommendations to the Board of Directors of
              the Company with respect to proposed amendments to the Plan;
       (viii) To file all reports with government agencies,
              Participants and other parties as may be required by law, whether
              such reports are initially the obligation of the Employers, or
              the Plan;
         (ix) To engage an actuary to the Plan, if necessary, and to cause
              the liabilities of the Plan to be evaluated by such actuary; and
          (x) To have all such other powers as may be necessary to
              discharge its duties hereunder.
     (b)  Decisions by the Administrator shall be final, conclusive and
binding on all parties and not subject to further review.
     (c)  The Administrator may employ attorneys, consultants,
accountants or other persons (who may be attorneys, consultants,
actuaries, accountants or persons performing other services for,
or are employed by, any Employer or any affiliate of any
Employer), and the Administrator, the Employers and their other
officers and directors shall be entitled to rely upon the advice,
opinions or valuations of any such persons.  No member of the
Board of Directors of any Employer, the Chief Executive Officer
of the Company, the Administrator, nor any other officer,
director or employee of the Company or of any Employer acting on
behalf of the Board of Directors of any Employer or the Chief
Executive Officer of the Company or the Administrator, shall be
personally liable for any action, determination or interpretation
taken or made in good faith with respect to the Plan, and all
members of the Boards of Directors of the Employers, the Chief
Executive Officer of the Company and the Administrator and each
officer or employee of the Company or of an Employer acting on
their behalf shall be fully indemnified and protected by the
Company for all costs, liabilities and expenses (including, but
not limited to, reasonable attorneys' fees and court costs)
relating to any such action, determination or interpretation.
     6.8  Binding Nature.  This Plan shall be binding upon and inure
to the benefit of the Employers and their successors and assigns
and to the Participants, their Beneficiaries and their estates.
Nothing in this Plan shall preclude any Employer from
consolidating or merging into or with, or transferring all or
substantially all of its assets to another company or
corporation, whether or not such company or corporation assumes
this Plan and any obligation of the Employer hereunder.
     6.9  Withholding Taxes.  The Employers may withhold from any
benefits payable under this Plan all federal, state, city or
other taxes as shall be required pursuant to any law or
governmental regulation or ruling.
     6.10 Action Affecting Chief Executive Officer.  To the extent any
action required to be taken by the Chief Executive Officer of the
Company would decrease, increase, accelerate, delay or otherwise
materially impact such individual's benefits under the Plan, such
action shall be taken instead by the Compensation Committee of
the Board of Directors of the Company.
     6.11 Payments Due Missing Persons.  The Administrator shall make
a reasonable effort to locate all persons entitled to benefits
(including retirement benefits and death benefits for
Beneficiaries) under the Plan; however, notwithstanding any
provisions of this Plan to the contrary, if, after a period of
five years from the date such benefits first become due, any such
persons entitled to benefits have not been located, their rights
under the Plan shall stand suspended.  Before this provision
becomes operative, the Administrator shall send a certified
letter to all such persons at their last known address advising
them that their benefits under the Plan shall be suspended.  Any
such suspended amounts shall be held by the Employer for a period
of three additional years (or a total of eight years from the
time the benefits first became payable) and thereafter such
amounts shall be forfeited and non-payable.
     6.12 Liability Limited.  Neither the Employers, the
Administrator, nor any agents, employees, officers, directors or
shareholders of any of them, nor any other person shall have any
liability or responsibility with respect to this Plan, except as
expressly provided herein.
     6.13 Incapacity.  If the Administrator shall receive evidence
satisfactory to it that a Participant or Beneficiary entitled to
receive any benefit under the Plan is, at the time when such
benefit becomes payable, a minor or is physically or mentally
incompetent to receive such benefit and to give a valid release
therefor, and that another person or an institution is then
maintaining or has custody of such Participant or Beneficiary and
that no guardian, committee or other representative of the estate
of such Participant or Beneficiary shall have been duly
appointed, the Administrator may make payment of such benefit
otherwise payable to such Participant or Beneficiary (or to such
guardian, committee or other representative of such person's
estate) to such other person or institution, and the release of
such other person or institution shall be a valid and complete
discharge for the payment of such benefit.
     6.14 Plurals.  Where appearing in the Plan, this singular shall
include the plural, and vice versa, unless the context clearly
indicates a different meaning.
     6.15 Headings.  The headings and sub-headings in this Plan are
inserted for the convenience of reference only and are to be
ignored in any construction of the provisions hereof.
     6.16 Severability.  In case any provision of this Plan shall be
held illegal or void, such illegality or invalidity shall not
affect the remaining provisions of this Plan, but shall be fully
severable, and the Plan shall be construed and enforced as if
said illegal or invalid provisions had never been inserted
herein.
     6.17 Payment of Benefits.  All amounts payable hereunder may be
paid directly by the Employer or pursuant to the terms of the
grantor trust, if any, established as a funding vehicle for
benefits provided hereunder.

         ARTICLE VII -- ADDITIONAL AFFILIATED COMPANIES

     7.1  Participation in the Plan.  (a)  Any Affiliated Company may
become an Employer with respect to this Plan with the consent of
the Chief Executive Officer of the Company, upon the following
conditions:
          (i) such Employer shall make, execute and deliver such
              instruments as the Company requires; and
         (ii) such Employer shall designate the Company, the Chief
              Executive Officer of the Company and the Administrator, as its
              agents for purposes of this Plan.
     (b)  Any such Employer may by action of its Board of Directors
withdraw from participation, subject to approval by the Chief
Executive Officer of the Company.
     7.2  Effect of Participation.  Each Employer which with the
consent of the Chief Executive Officer of the Company complies
with Section 7.1(a) shall be deemed to have adopted this Plan for
the benefit of its Employees who participate in this Plan.

     IN WITNESS WHEREOF, the Company, as the sponsoring employer of the
Plan, Has caused this Plan document to be duly executed by its
President and Chief Executive Officer on this 17th day of
February, 2005.

                              MDU RESOURCES GROUP, INC.




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



                              APPENDIX A
             SCHEDULE OF RETIREMENT AND SURVIVORS BENEFITS


                                      Monthly           Monthly
    Level       Salary              Retirement           Death
                                      Benefit           Benefit

     50        $50,000-$59,999         $1,330            $2,660
     51                                $1,728            $3,456
     52        $60,000-$74,999         $1,800            $3,600
     53                                $2,160            $4,320
     54        $75,000-$99,999         $2,580            $5,160
     55                                $2,880            $5,760
     56      $100,000-$124,999         $3,600            $7,200
     57      $125,000-$149,999         $4,470            $8,940
     58      $150,000-$174,999         $5,360           $10,720
     59      $175,000-$199,999         $6,250           $12,500
     60      $200,000-$224,999         $7,300           $14,600
     61      $225,000-$249,999         $8,215           $16,430
     62      $250,000-$274,999         $9,125           $18,250
     63      $275,000-$299,999        $10,475           $20,950
     64      $300,000-$324,999        $12,145           $24,290
     65      $325,000-$349,999        $13,670           $27,340
     66      $350,000-$399,999        $16,110           $32,220
     67      $400,000-$449,999        $19,525           $39,050
     68      $450,000-$499,999        $22,850           $45,700
     69      $500,000-$599,999        $28,800           $57,600
     70      $600,000-$699,999        $36,500           $73,000
     71      $700,000-$799,999        $42,710           $85,420
     72      $800,000-$899,999        $49,220           $98,440
     73      $900,000-$999,999        $55,310          $110,620
     74  $1,000,000-$1,099,999        $60,200          $120,400



                           APPENDIX B
   CURRENT PARTICIPANTS ELIGIBLE FOR ARTICLE IV BENEFITS


Steven L. Bietz
John K. Castleberry
Terry D. Hildestad
Bruce T. Imsdahl
Vernon A. Raile
Warren L. Robinson
Paul K Sandness
William E. Schneider
Martin A. White