FIRM STORAGE SERVICE AGREEMENT

Questar Pipeline Company                                         
79 South State Street
Salt Lake City, Utah  84111                    Contract No. STO46


     THIS AGREEMENT is entered into this 12th day of April, 1993, by and
between QUESTAR PIPELINE COMPANY, CLAY BASIN STORAGE DIVISION, a Utah
corporation, "Seller," and MOUNTAIN FUEL SUPPLY COMPANY, "Buyer."

     Buyer represents that it desires Seller to store natural gas in Seller's
Clay Basin Storage Field; and Seller represents that it is seeking FERC
authorization to expand the storage capacity available in order to provide the
storage service for Buyer on the terms specified in this agreement.

     Seller and Buyer agree as follows:

                         AGREEMENT TERMS

     The terms selected below, together with the terms and conditions of this
agreement, including the attached Appendices A and B, constitute the storage
service to be provided and the rights and obligations of the parties.  Buyer
shall designate receipt and delivery points on Appendix A that are acceptable
to Seller.

1.  BUYER'S STATUS (Please Check One Only):

         XX         Local Distribution Company
                    Intrastate Pipeline Company
                    Interstate Pipeline Company
                    Marketer/Broker
                    Producer
                    End-User
                    Other (Specify) _______________

2.  VOLUMES TO BE INJECTED AND WITHDRAWN (Subject to the provisions of Section
8, below):

     Firm Service (Please see note below for MRD calculation):

       5,500    Annual Working Gas Volume (MMcf)
       45.83    Minimum Required Deliverability Volume MMcf/day (MRD)


          
          Note:  MRD must be calculated using the formula shown below:

               MRD = Annual Working Gas Volume (MMcf/year)
                              150 days x .80

3.   RATES (Subject to the provisions of paragraph 2 of Appendix B):

     Firm Storage Service - Rate Schedule FSS
     DEMAND CHARGES:

     Deliverability (Please Check One Only):

          XX        the maximum rate set forth in Seller's Statement of Rates
                    a discounted rate of $___________/Mcf

     Inventory Capacity (Please Check One Only):
     
          XX        the maximum rate set forth in Seller's Statement of Rates
                    a discounted rate of $___________/Mcf

     Prior to the time the terms and conditions set forth in Appendix B are
     met to the sole satisfaction of Seller, demand charges under this
     agreement shall be applied to the levels of Annual Working Gas Volume
     and MRD that Seller, in Seller's sole judgement, can actually provide in
     the event the Annual Working Gas Volume and MRD requested by Buyer and
     set forth in Section 2 above cannot reasonably be commenced.  Unless Seller
     notifies Buyer in writing that Seller is unable to provide the service
     at the requested levels, Buyer shall be responsible for all demand
     charges, as set forth above in this Section 3.

     COMMODITY CHARGES:

     Injection:     $0.00851/Mcf

     Withdrawal:    $0.01631/Mcf

     Overrun:  $0.29124/Mcf


4.   ACA CHARGE:
         XX         yes
                    no

5.   ADDITIONAL FACILITIES CHARGES:
     Additional facilities:
         XX    are required
                    are not required

     Charge:
        N/A         lump-sum payment of $ ____________
        N/A         monthly fee of $ ____________

6.   TERM OF THE AGREEMENT (Subject to the provisions of Section 8, below):

     (a)  Initial term 

          May 15, 1994 to May 14, 2019

     (b)  Renewal term
         XX         none
                    other:  __________________________

     (c)  Termination.  This agreement shall be renewed as stated in Section
6(b) above.  This agreement may be terminated during any renewal period
          by either party upon 30 days' written notice to the other party
          prior to each injection period.

7.   NOTICE:  Unless otherwise provided in Seller's FERC Gas Tariff, Volume
No. 2-A, all notices shall be given by telephone or other electronic means and
confirmed in writing at the following addresses:

Buyer:

Mountain Fuel Supply Company
141 East First South Street
Salt Lake City, Utah  84147

Attention:     Vice President - Gas Supply
Telephone:     (801) 530-2043
Fax:           (801) 530-2970


QUESTAR PIPELINE COMPANY
79 South State Street
Salt Lake City, Utah  84111
Attn:  Director, Gas Supply Planning
Telephone:  (801) 530-2020
Fax:  (801) 530-2570

8.   COMMENCEMENT OF SERVICE:  Seller shall not be obligated to commence the
requested Clay Basin expansion service under this agreement until all terms
and conditions of Appendix B are met to the sole satisfaction of Seller. 
However, at any time prior to such fulfillment of the Appendix B terms and
conditions, service may, if deemed feasible solely by Seller, be made
available to Buyer using the priority determined by applying the present value
ranking procedures set forth in Section 4.2 of Seller's FERC Gas Tariff,
Original Volume No. 2-A to the effective service requests underlying the
executed expansion service agreements.  Service to remaining Buyers will
commence as soon as deemed operationally practicable by Seller.

     If the FERC authorizes only a portion of the total expansion capacity
requested by Seller and the authorized capacity is oversubscribed by Buyers
who have executed a tendered firm storage service agreement, then the capacity
so approved will be made available to such Buyers using the priority
determined by applying the present value ranking procedure set forth in Section
4.2 of Seller's FERC Gas Tariff, Original Volume No. 2-A to the respective
executed service agreements.  Service agreements receiving no allocation of
capacity under this methodology, and the respective underlying requests for
service, shall be considered void for all purposes.

9.   TARIFF:  This agreement shall be subject to the terms and conditions
attached to and made part of this agreement as Appendix B and all the
applicable rate schedules and the General Terms and Conditions of Seller's
FERC Gas Tariff, Original Volume No. 2-A, as it may be amended or superseded
from time to time.

10.  RESTRUCTURING TARIFF:  Upon implementation by Seller of tariff changes
required by the FERC to comply with restructuring under Order No. 636 in
Docket No. RS92-9, this agreement will be reformed to conform to Seller's
tariff.  The reformed agreement will be issued to Buyer according to the
procedures set forth in Seller's tariff, as it may be amended or superseded
from time to time.


The parties have executed this agreement to be effective the first day of its
term.

BUYER: Mountain Fuel Supply Co.    QUESTAR PIPELINE COMPANY
By:   /s/ M. E. Benefield          By:  /s/ J. B. Carricaburu
Title: Vice President Gas Supply   Title: V. P., Gas Supply & Marketing
Date:      March 25, 1993               Date:     April 12, 1993


                            APPENDIX A


                        1.  Receipt Points

Description                                          Quantity/Mcf


                                 


                       2.  Delivery Points


Description                                          Quantity/Mcf






                             APPENDIX B

                 CONDITIONS PRECEDENT TO SERVICE

1.   Seller shall not be obligated to provide expanded firm storage service
at Clay Basin under this agreement until the following conditions are met to
the sole satisfaction of Seller:

     a.   Receipt by Seller of signed firm storage service agreements from
     one or more Buyers for sufficient capacity and upon terms and conditions
     acceptable to Seller that justify construction of the Clay Basin
     expansion;

     b.   Receipt and acceptance by Seller of all approvals required to
     expand the capacity at Clay Basin as requested by Seller and to
     construct the facilities necessary to provide all expanded firm storage
     service requested by all expansion Buyers and to commence the service,
     including all necessary authorizations from federal, state and local
     municipal agencies and other government authorities, in final form and
     substance satisfactory to Seller, permitting or authorizing the service;

     c.   Receipt and acceptance by Seller of all necessary rights of way,
     easements and permits, if any, required to construct, operate and
     maintain the Clay Basin expansion facilities;

     d.   Completion of construction and commencement of actual operation of
     all facilities, including injection of all required cushion gas,
     necessary to provide firm storage service to all expansion buyers.

2.   Should the FERC approve Clay Basin storage rates for firm service above
the rates in effect on February 12, 1993, and such increase is due solely to
costs associated directly with the expansion of Clay Basin, Buyer may
terminate this agreement.

3.   Buyer's creditworthiness shall remain a continuing condition precedent
to Seller's obligation to perform.  Seller may require Buyer to reverify its
creditworthiness as Seller deems necessary.