<PAGE>   1

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                          PURCHASE AND SALE AGREEMENT
                                [DIRECT PACKAGE]


                                    BETWEEN


                               HS RESOURCES, INC.


                                      AND


                           WESTTIDE INVESTMENTS, LLC



                            DATED: DECEMBER 15, 1997

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<PAGE>   2
                              TABLE OF CONTENTS
<TABLE>
<CAPTION>
                                                                                                                     Page
                                                                                                                     ----
<S>       <C>                                                                                                          <C>
1.        Advance and Purchase  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   1
          1.1       Advance of Funds  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   1
          1.2       Purchase and Sale of Rights under Amoco Agreement   . . . . . . . . . . . . . . . . . . . . . . .   1

2.        The Assets  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   2
          2.1       Leases and Wells  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   2
          2.2       Incidental Rights   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   2

3.        Effective Date  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   2

4.        Tax Credit Payments   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   3

5.        Apportionment of Production, Revenues, Taxes and other Expenses   . . . . . . . . . . . . . . . . . . . . .   4

6.        Buyer's Representations and Warranties  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   4
          6.1       Existence   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   4
          6.2       Power and Authority   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   4
          6.3       Authorization   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
          6.4       Execution and Delivery  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   4
          6.5       Securities Laws   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   5
          6.6       Brokers' Fees   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   5

7.        Seller's Representations and Warranties   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   5
          7.1       Existence   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   5
          7.2       Power and Authority   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   5
          7.3       Authorization   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   5
          7.4       Execution and Delivery  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   5
          7.5       Brokers' Fees   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   6
          7.6       Reserve Report  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   6
          7.7       Liens   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   6
          7.8       Title   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   8
          7.9       Preferential Purchase Rights and Consents   . . . . . . . . . . . . . . . . . . . . . . . . . . .   8
          7.10      No Prepayments  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   8
          7.11      Gas Balancing   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   8
          7.12      Leases  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   8
          7.13      Operations in Progress  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   9
          7.14      Hydrocarbon Sales Contracts   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
          7.15      Proceeds of Production  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   9
          7.16      Material Contracts  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   9
          7.17      Bills in the Ordinary Course  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   9
          7.18      Legal Proceedings   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .   9
          7.19      Compliance with Laws  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  10
          7.20      Environmental Matters   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  10
          7.21      Payment of Taxes  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  10
</TABLE>


                                     (i)

<PAGE>   3
<TABLE>
<S>       <C>                                                                                                         <C>
          7.22      Tax Partnerships  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  10
          7.23      Other Tax Matters   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  11

8.        Certain Tax Matters   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  12
          8.1       Opinion of Tax Counsel, Right to Request Ruling   . . . . . . . . . . . . . . . . . . . . . . . .  12
          8.2       Tax Status  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  13
          8.3       Escrow in the Event of Tax Audit  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  13
          8.4       Settlements Resulting from a Tax Audit  . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  14

9.        Covenants   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  14
          9.1       Cooperation and Access  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  14
          9.2       Insurance   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  14

10.       Closing Conditions  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  14
          10.1      Seller's Closing Conditions   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  14
          10.2      Buyer's Closing Conditions  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  15

11.       Closing   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  15
          11.1      Advance   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  15
          11.2      Section 15.2 Payment  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  15
          11.3      Notice of Preferential Rights and Consents  . . . . . . . . . . . . . . . . . . . . . . . . . . .  16
          11.4      Assignments; Recourse Note; Option  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  16
          11.5      Non-Foreign Ownership Affidavits  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  16
          11.6      Evidence of Insurance   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  16
          11.7      Contribution Agreement  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  16
          11.8      Guaranty Agreement  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  16
          11.9      Seller's Officer's Certificate  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  16
          11.10     Opinion on Behalf of Seller   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  16
          11.11     Buyer's Manager's Certificate   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  16
          11.12     Opinion on Behalf of Buyer  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  17
          11.13     Management Agreement  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  17
          11.14     Performance Power of Attorney   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  17
          11.15     Tax Opinion   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  17
          11.16     Additional Instruments  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  17

12.       Post-Closing Matters  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  17
          12.1      Files and Records   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  17
          12.2      Sales Taxes and Recording Fees  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  17
          12.3      Rebates for Defective Interests   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  17
          12.4      Rebates for Exercised Preferential Purchase Rights, Failure to Obtain Consents  . . . . . . . . .  18
          12.5      Reconveyance of Excluded Assets   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  18
          12.6      Allocation of Commingled Production and Costs   . . . . . . . . . . . . . . . . . . . . . . . . .  18
          12.7      Performance of Buyer  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  19
          12.8      Overpayments  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  19

13.       Apportionment of Liabilities and Obligations  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  19
</TABLE>





                                      (ii)
<PAGE>   4
<TABLE>
<S>       <C>                                                                                                        <C>
          13.1      Buyer   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  19
          13.2      Seller  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  19

14.       Indemnification   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  20
          14.1      Buyer's Indemnification of Seller   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  20
          14.2      Seller's Indemnification of Buyer   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  20
          14.3      Third Party Claims  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  21

15.       Miscellaneous   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  21
          15.1      Further Assurances  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  21
          15.2      Expenses  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  21
          15.3      Notices   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  21
          15.4      Survival  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  22
          15.5      Confidentiality   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  22
          15.6      Announcements   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  22
          15.7      Assignment  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  23
          15.8      Binding Effect  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  23
          15.9      Complete Agreement  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  23
          15.10     Knowledge   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  23
          15.11     Governing Law   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  23
          15.12     Counterparts  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .  23
</TABLE>





                                      (iii)
<PAGE>   5
                                    EXHIBITS

<TABLE>
<S>                 <C>
Exhibit A           Leases (Colorado)
Exhibit B           Wells (showing WI, NRI, qualifying formations)
Exhibit C           Form of Wellbore Assignment of Oil and Gas Leases
Exhibit D           Form of Assignment of Production Payment and Future
                    Interest (with Form of Recourse Promissory Note)
Exhibit E           Form of Option to Purchase Oil and Gas Interests
Exhibit F           Reserve Report
Exhibit G           Preferential Purchase Rights and Consents
Exhibit H           Prepayments and Gas Imbalances
Exhibit I           Operations in Progress
Exhibit J           Hydrocarbon Sales Contracts
Exhibit K           Legal Proceedings
Exhibit L           Tax Partnerships
Exhibit M           Well List - No NGPA Certification Received
                    Part I  - Uphole Recompletions
                    Part II - Wells Timely Drilled
Exhibit N           Form of Non-Foreign Ownership Affidavits
Exhibit O           Form of Contribution Agreement and Form of Guaranty Agreement
Exhibit P           Form of Seller's Officer's Certificate
Exhibit Q           Form of Opinion on Behalf of Seller
Exhibit R           Form of Buyer's Manager's Certificate
Exhibit S           Form of Opinion on Behalf of Buyer
Exhibit T           Form of Management Agreement
Exhibit U           Form of Escrow Agreement
Exhibit V           Form of Limited Power of Attorney
</TABLE>





                                     (iv)
<PAGE>   6
                          PURCHASE AND SALE AGREEMENT


         This Purchase and Sale Agreement [Direct Package] (this "Agreement"),
dated December 15, 1997, is between HS Resources, Inc., a Delaware corporation
("Seller" or "HSR") and WestTide Investments, LLC, a Delaware limited liability
company ("Buyer" or "WestTide").

         RECITALS

         A.      Pursuant to that certain Purchase and Sale Agreement dated
November 25, 1997 between Amoco Production Company ("Amoco") and Seller (the
"Amoco Agreement"), Seller is the owner of the right to acquire certain oil and
gas leasehold interests in Colorado, as more specifically described below in
Section 2 (the "Assets").

         B.      Seller desires to sell its right to acquire the Assets, and
Seller is willing to advance to Buyer a portion of the funds required to
purchase the Assets from Amoco.

         C.      Seller and Buyer are parties to that certain Acquisition and
Nominee Agreement dated December 15, 1997 (the "Nominee Agreement"), wherein
Seller will acquire and hold record title to the Assets for and on behalf of
Buyer as Buyer's nominee.

         D.      Buyer desires to purchase the Assets subject to the obligation
to repay the advance from Seller and the terms and conditions of the Nominee
Agreement and this Agreement.

         AGREEMENT

         IN CONSIDERATION of the mutual benefits contemplated herein and other
good and valuable consideration, the receipt and sufficiency of which are
hereby acknowledged, Seller and Buyer agree as follows:

         1.      Advance and Purchase.

                 1.1      Advance of Funds.  Seller agrees to advance to Buyer
a portion of the funds required to purchase the Assets from Amoco.  At Closing,
Seller shall make a cash advance to Buyer in the amount of $57,633,009 (the
"Advance").  In consideration for the Advance, Buyer shall convey to Seller a
junior net profits production payment in the Assets (the "Production Payment"),
and a senior recourse promissory note (the "Recourse Note") as set forth in the
Assignment of Production Payment and Future Interest in a form substantially
similar to Exhibit D (the "Production Payment Assignment").  Buyer will make
the proceeds of the Advance, as well as other funds, available to Seller as
Buyer's nominee under the Nominee Agreement to acquire the Assets on behalf of
Buyer under the Amoco Agreement.

                 1.2      Purchase and Sale of Rights under Amoco Agreement.
In consideration for Buyer (i) conveying to Seller (a) a future interest in the
Assets (the "Future Interest") as set forth in the Production Payment
Assignment, and (b) the Option To Purchase Oil and Gas





<PAGE>   7
Interests in a form substantially similar to Exhibit E (the "Option"); and (ii)
agreeing to pay to Seller in the future the Credit Payment Amounts set forth
below in Section 4, Seller agrees to convey its right under the Amoco Agreement
to acquire the Assets to Buyer and Buyer agrees to purchase the Assets, all
pursuant to the terms and conditions of this Agreement, the Nominee Agreement
and the Wellbore Assignment of Oil and Gas Leases in a form substantially
similar to Exhibit C (the "Wellbore Assignment").  As between Buyer and Seller
under this Agreement, the portion of the purchase price under the Amoco
Agreement allocated to the Assets shall be $67,392,009.

         2.      The Assets.  The "Assets" shall be all of the following:

                 2.1      Leases and Wells.  Seller's right, title and interest
in and to the oil and gas leases and mineral interests described in Exhibit A,
including any and all overriding royalty interests owned by Seller in such
leases, but insofar and only insofar as said leases and interests cover the
right to receive proceeds of production from the wells described in Exhibit B
from the intervals referenced in Section 7.23 and identified in Exhibit B in
such wells as of the Effective Date (the above described interest in such
leases being herein called the "Leases" and the above described interest in
such wells being herein called the "Wells"), and subject to any restrictions,
exceptions, reservations, conditions, limitations, burdens, contracts,
agreements and other matters applicable to such Leases and Wells.

                 2.2      Incidental Rights.  All of Seller's right, title and
interest in and to the following insofar and only insofar as same are
attributable to the Leases and the Wells:

                          (a)       Unitization and Pooling Agreements.  All
         presently existing and valid oil, gas or mineral unitization, pooling,
         operating and communitization agreements, declarations and orders
         affecting the Leases and Wells, and in and to the properties covered
         and the units created thereby;

                          (b)       Personal Property.  The personal property
         and fixtures that are appurtenant to the Wells, including all wells,
         casing, tubing, pumps, separators, tanks, lines and other personal
         property and oil field equipment appurtenant to such Wells;

                          (c)       Agreements.  All presently existing and
         valid oil and gas sales, purchase, production swap, gathering and
         processing contracts and operating agreements, joint venture
         agreements, partnership agreements, rights-of-way, easements, permits,
         surface leases and other contracts, agreements and instruments, but
         specifically excluding any management agreements.

Seller shall remain co-owner of any "Agreements," "Personal Property" and
"Unitization and Pooling Agreements" to the extent they pertain to any property
or formation owned by Seller that is not exclusively part of the Wells.

         3.      Effective Date.  The purchase and sale of the Assets shall be
effective, for all purposes, including allocation of revenue, expenses and
taxes, as of December 15, 1997 at 7:00 a.m. local time at the site of the
Assets (the "Effective Date").





                                      -2-
<PAGE>   8
         4.      Tax Credit Payments.  Following the Effective Date, Buyer
shall pay to Seller the Credit Payment Amounts.  "Credit Payment Amount" shall
mean, for any Payment Period, an amount equal to $0.70 of each dollar of tax
credits (the "Tax Credits") available to Buyer under Section  29 of the
Internal Revenue Code of 1986, as amended (the "IRC"), as a result of the sale
of Subject Hydrocarbons by or on behalf of Buyer, to the extent that such
Subject Hydrocarbons (i) constitute "qualified fuels" within the meaning of IRC
Section  29(c), (ii) meet the requirements of IRC Sections  29(d)(1), 29(d)(4)
and 29(f), during (x) such Payment Period and (y) any earlier Payment Period to
the extent the dollar amount of Tax Credits attributable thereto was not taken
into account in a Credit Payment Amount for a previous Payment Period, and
(iii) are produced from the Wells.  For purposes of the preceding sentence, Tax
Credits available to Buyer under IRC Section  29 shall be determined after
taking into account any phase-out of Tax Credits under IRC Section  29(b)(1)
and any applicable inflation adjustment under IRC Section  29(b)(2), but shall
be determined without regard to limitations on Buyer's or its affiliate's use
of Tax Credits imposed by IRC Section  29(b)(6) and without regard to whether
Buyer or its affiliates actually utilize such Tax Credits.  The Credit Payment
Amount for any given Payment Period shall initially be based on estimated
Subject Hydrocarbon production and sales data available at the time of the
calculation of such amount and later corrected when actual data is available.
The Credit Payment Amount shall be determined on the assumption that (i) the
Production Payment is treated as a production payment for federal income tax
purposes, (ii) Buyer is treated as owning the economic interest in minerals in
place in the Assets, and (iii) the Recourse Note is treated as debt for federal
income tax purposes.  Credit Payment Amounts shall be calculated and, unless
otherwise provided herein, will be due and payable within fifteen (15) days of
Buyer's receipt (by overnight courier or facsimile) of an invoice for payment
(except as provided below in this Section 4) with respect to gas produced and
sold from December 15, 1997 until the earlier of (x) the aggregate of all
Credit Payment Amounts computed pursuant to this Agreement equals $12,700,000
(subject to the provisions of Paragraph 1.a.(vii) of the Option), (y) December
31, 2002, or (z) the first day on which Tax Credits are no longer permitted for
gas attributable to the Subject Hydrocarbons and produced and sold from the
Wells.  If for any reason the Tax Credits are repealed by Congressional statute
or resulting regulation, no Credit Payment Amount shall be due with respect to
Subject Hydrocarbons subject to such repeal.  If for any reason the amount of
Tax Credits contemplated under this Agreement are reduced by Congressional
statute or resulting regulation, the Credit Payment Amounts due under this
Agreement shall be reduced commensurate with such reduction in Tax Credits.
For purposes of the foregoing, the terms "Subject Hydrocarbons" and "Payment
Period" shall have the meanings set forth in the Production Payment Assignment.

         Notwithstanding any of the provisions of the preceding paragraph in
this Section 4, Buyer shall have no obligation to pay the first $6,562,000 in
Credit Payment Amounts determined in accordance with the preceding paragraph
(the "Credit Threshold").  If the Credit Threshold exceeds the aggregate of
actual Credit Payment Amounts determined under the preceding paragraph as of
December 31, 2002, Buyer shall be treated as having made an overpayment of
Credit Payment Amounts in an amount equal to such excess and such excess shall
be paid by Seller to Buyer on or before February 1, 2003.  Buyer shall not have
any right to require or cause an acceleration or recoupment of any such excess
prior to January 1, 2003.  If Seller exercises the Option with respect to
twenty-five percent (25%) or more, in the aggregate, of the reserves





                                      -3-
<PAGE>   9
attributable to the Assets at any time prior to January 1, 2003, then Seller
shall pay to Buyer an amount, if any, equal to the excess of the Credit
Threshold over the aggregate of actual Credit Payment Amounts determined under
the preceding paragraph as of the effective date the Option is exercised.

         5.      Apportionment of Production, Revenues, Taxes and other
Expenses.  Buyer shall be entitled to revenue from the sale of hydrocarbons
produced from the Wells on or after the Effective Date, subject to the
Production Payment, Future Interest and the Option.  Buyer shall pay for costs
and expenses incurred with respect to the Assets on or after the Effective
Date.  Seller shall be entitled to revenue from the sale of hydrocarbons
produced from the Wells before the Effective Date, and shall pay for costs and
expenses incurred with respect to the Assets prior to the Effective Date.
Taxes relating to the Assets, including ad valorem, property, production,
severance and other taxes (other than income taxes) shall be allocated in the
same manner as other expenses.  Taxes that are measured by or that relate to
production shall be treated as expenses in connection with such production
regardless of the period for which such taxes are assessed.

         6.      Buyer's Representations and Warranties.  Buyer makes the
following representations and warranties as of the date of execution of this
Agreement:

                 6.1      Existence.  Buyer is a limited liability company,
duly organized, validly existing and formed under the law of the State of
Delaware, and Buyer is duly qualified to carry on its business, and is duly
qualified and in good standing, in each of the states in which the nature of
its business and activities requires it to be so qualified.

                 6.2      Power and Authority.  Buyer has all requisite power
and authority to carry on its business as presently conducted, to enter into
this Agreement and each of the documents contemplated to be executed by Buyer
at Closing, and to perform its obligations under this Agreement and under such
documents.  The consummation of the transactions contemplated by this Agreement
and each of the documents contemplated to be executed by Buyer at Closing will
not violate, nor be in conflict with, (i) any provision of Buyer's
organizational or governing documents, (ii) any material agreement or
instrument to which Buyer is a party or is bound, or (iii) any judgment,
decree, order, statute, rule or regulation applicable to Buyer.

                 6.3      Authorization.  The execution, delivery and
performance of this Agreement and each of the documents contemplated to be
executed by Buyer at Closing and the transactions contemplated hereby and
thereby have been duly and validly authorized by all requisite action on the
part of Buyer.

                 6.4      Execution and Delivery.  This Agreement has been duly
executed and delivered on behalf of Buyer, and at the Closing all documents,
instruments and schedules required hereunder to be executed and delivered by
Buyer shall have been duly executed and delivered.  This Agreement does, and
such documents and instruments shall, constitute legal, valid and binding
obligations of Buyer enforceable in accordance with their terms, subject to (i)
applicable bankruptcy, insolvency, reorganization, moratorium and other similar
laws of





                                      -4-
<PAGE>   10
general application with respect to creditors, (ii) general principles of
equity and (iii) the power of a court to deny enforcement of remedies generally
based upon public policy.

                 6.5      Securities Laws.  Buyer is purchasing the Assets for
Buyer's own account, not for public distribution thereof, and Buyer shall not
sell or transfer all or any part of, or any interest in, the Assets in
violation of the Securities Act of 1933, as amended, and the rules and
regulations thereunder, or the securities laws of any state.

                 6.6      Brokers' Fees.  Buyer has incurred no liability,
contingent or otherwise, for brokers' or finders' fees relating to the
transactions contemplated by this Agreement for which Seller shall have any
responsibility whatsoever.

         7.      Seller's Representations and Warranties.  Seller makes the
following representations and warranties as of the date of this Agreement:

                 7.1      Existence.  Seller is a corporation duly organized
and validly existing under the law of the State of Delaware, and Seller is duly
qualified to carry on its business, and is in good standing in the States of
Delaware and Colorado.

                 7.2      Power and Authority.  Seller has all requisite
authority to carry on its business as presently conducted, to enter into this
Agreement and each of the documents contemplated to be executed by Seller at
Closing, and to perform its obligations under this Agreement and under such
documents.  The consummation of the transactions contemplated by this Agreement
and each of the documents contemplated to be executed by Seller at Closing will
not violate, nor be in conflict with, (i) any provision of Seller's Certificate
of Incorporation, bylaws or other governing documents, (ii) any material
agreement or instrument to which Seller is a party or is bound, or (iii) any
judgment, decree, order, statute, rule or regulation applicable to Seller;
provided that, the representations and warranties contained in clauses (ii) and
(iii) of this Section 7.2 are subject to (a) consents of or filings with the
United States Department of Interior or the applicable state agencies or
authorities in connection with the assignment of any federal or state leases or
any interest therein to the extent such consents are typically received or
filings typically made subsequent to such assignment ("Governmental Consents"),
(b) preferential rights to purchase all or any portion of the Assets and
consent to or notices of assignment necessary to convey all or any portion of
the Assets which are not Governmental Consents, and (c) any violation of any
maintenance of uniform interest provision in any applicable operating
agreement.

                 7.3      Authorization.  The execution, delivery and
performance of this Agreement and each of the documents contemplated to be
executed by Seller at Closing and the transactions contemplated hereby and
thereby have been duly and validly authorized by all requisite corporate action
on the part of Seller.

                 7.4      Execution and Delivery.  This Agreement has been duly
executed and delivered on behalf of Seller, and at the Closing all documents,
instruments and schedules required hereunder to be executed and delivered by
Seller will be duly executed and delivered.  This Agreement does, and such
documents and instruments shall, constitute legal, valid and





                                      -5-
<PAGE>   11
binding obligations of Seller enforceable in accordance with their terms,
subject to (i) applicable bankruptcy, insolvency, reorganization, moratorium
and other similar laws of general application with respect to creditors, (ii)
general principles of equity and (iii) the power of a court to deny enforcement
of remedies generally based upon public policy.

                 7.5      Brokers' Fees.  Seller has incurred no liability,
contingent or otherwise, for brokers' or finders' fees relating to the
transactions contemplated by this Agreement for which Buyer shall have any
responsibility whatsoever.

                 7.6      Reserve Report.  The term "Reserve Report" shall mean
the reserve report prepared by Seller which is based on reserves as of December
31, 1996, and attached hereto as Exhibit F.  To Seller's best knowledge, the
average price for sales of hydrocarbons (based on contract prices for existing
effective contracts and estimates of regional spot prices adjusted for regional
transportation costs), historical costs of operations, production volumes, and
payout data used by Seller in the preparation of the Reserve Report were, on
the dates so used, accurate in all material respects.

                 7.7      Liens.  Except for the burdens and obligations
created by or arising under the Leases and except for Permitted Encumbrances,
the Assets are free and clear of all Encumbrances.  As used herein, the term
"Encumbrances" shall mean all royalties, overriding royalties, production
payments, debts, liens, mortgages, security interests, and encumbrances.  As
used herein, the term "Permitted Encumbrances" shall mean the following:

                          (i)     the burdens, encumbrances and obligations
         created by or arising under the Wells and other agreements affecting
         the Assets, and all royalties, overriding royalties, net profits
         interests, carried interests, reversionary interests, back-in rights
         and other burdens taken into account in computing the net revenue
         interests ("NRI") and working interests ("WI") set forth on Exhibit B
         for the Wells;

                          (ii)    all rights to consent by, required notices
         to, filings with, or other actions by governmental entities in
         connection with the sale or conveyance of the Assets if the same are
         customarily obtained subsequent to such sale or conveyance;

                          (iii)   rights of reassignment upon surrender of the
         Leases held by predecessors in interest to Seller;

                          (iv)    easements, rights-of-way, servitudes,
         permits, licenses, surface leases and other rights in respect of
         surface use to the extent these do not materially interfere with
         operations or production on or from the Assets;

                          (v)     rights and regulatory powers reserved to or
         vested in any municipality or governmental, statutory or public
         authority;

                          (vi)    all Material Contracts to the extent same do
         not reduce Seller's interest in the production from the Wells to less
         than the NRI set forth on Exhibit B;





                                      -6-
<PAGE>   12
                          (vii)   any (a) undetermined or inchoate liens or
         charges constituting or securing the payment of expenses which were
         incurred incidental to maintenance, development, production or
         operation of the Assets or for the purpose of developing, producing or
         processing oil, gas or other hydrocarbons therefrom or therein and (b)
         materialman's, mechanics', repairman's, employees', contractors',
         operators' or other similar liens, security interests or charges for
         liquidated amounts arising in the ordinary course of business
         incidental to construction, maintenance, development, production or
         operation of the Assets or the production or processing of oil, gas or
         other hydrocarbons therefrom, that are not delinquent and that will be
         paid in the ordinary course of business or, if delinquent, that are
         being contested in good faith;

                          (viii)  any liens for taxes not yet delinquent or, if
         delinquent, that are being contested in good faith in the ordinary
         course of business;

                          (ix)    any liens or security interests created by
         law or reserved in Leases for royalty, bonus or rental or for
         compliance with the terms of the Leases;

                          (x)     any prohibitions or restrictions similar to
         the Maintenance of Uniform Interest Provisions contained in Article
         VIII.D. of the A.A.P.L. Form 610-1982 Model Form Operating Agreement
         and any contribution obligations under provisions similar to Article
         VII.B of such Model Form Operating Agreement;

                          (xi)    all preferential rights to purchase all or
         any portion of the Assets and consents to or notices of assignment
         necessary to convey all or any portion of the Assets which are not
         described in item (ii) of this definition of Permitted Encumbrances;

                          (xii)   all agreements and obligations relating to
         imbalances with respect to the production, transportation or
         processing of gas or calls or purchase options on oil or gas
         production;

                          (xiii)  all agreements and obligations relating to
         gathering, transportation or processing of gas or oil production;

                          (xiv)   all treating, processing, sales or marketing
         agreements which have a fee which is based on a percentage of proceeds
         or an obligation to transfer certain volumes of gas or oil production
         in- kind;

                          (xv)    all obligations by virtue of a prepayment,
         advance payment or similar arrangement under any contract for the sale
         of gas production, including by virtue of "take or pay" or similar
         provisions, to deliver gas produced from or attributable to the Wells
         after the Effective Date without then or thereafter being entitled to
         receive full payment therefor;

                          (xvi)   all liens, charges, encumbrances, contracts,
         agreements, instruments, obligations, defects, irregularities and
         other matters affecting any Asset





                                      -7-
<PAGE>   13
         which individually or in the aggregate will not interfere materially
         with the operation, value or use of such Asset;

                          (xvii)  the burdens, encumbrances and obligations
         created by or arising under this Agreement, the Wellbore Assignment,
         Production Payment Assignment, Option or Management Agreement; and

                          (xviii) all matters identified as "Permitted
         Encumbrances" under the Amoco Agreement.

                 7.8      Title.  Subject to Seller's right to bring claims
against Amoco for a period of 120 days following the Closing Date based upon
Seller's due diligence evaluations pursuant to Section 4.2 of the Amoco
Agreement, Buyer will receive Defensible Title to the Assets.  The term
"Defensible Title" means such title to the Leases that, subject to and except
for the Permitted Encumbrances and the terms of the Amoco Agreement, entitles
Buyer to receive an interest in production from the Wells not less than the
respective NRIs in the Wells as set forth on Exhibit B, and entitles Buyer to
own the respective WIs in the Wells as set forth on Exhibit B under applicable
state law and for federal income tax purposes.  Any Well or Lease for which
there is less than Defensible Title as of the date of this Agreement shall be
called a "Defective Interest."  Buyer's exclusive remedy for Seller's breach of
this representation and warranty is set forth in Section 12.3.  Buyer and
Seller shall cooperate fully and consult in good faith with each other in the
litigation of any matter identified in this Section 7.8

                 7.9      Preferential Purchase Rights and Consents.  To
Seller's best knowledge, except as set forth in Exhibit G and subject to
Seller's rights under Sections 3.4 and 3.5 of the Amoco Agreement, there do not
exist any preferential rights to purchase all or any portion of the Assets.  To
Seller's best knowledge, except for Governmental Consents and other matters as
set forth in Exhibit G, there are no consents or waivers necessary to convey
any material portion of the Assets pursuant to this Agreement. Buyer's
exclusive remedy for Seller's breach of this representation and warranty is set
forth in Section 12.4.

                 7.10     No Prepayments.  To Seller's best knowledge, except
as set forth in Exhibit H, there is no obligation, by virtue of a prepayment
arrangement, a "take or pay" arrangement, a production payment, hedging or any
other arrangement, to deliver any material portion of hydrocarbons produced
from the Wells at some future time without then or thereafter receiving full
payment therefor.

                 7.11     Gas Balancing.  To Seller's best knowledge, except as
set forth in Exhibit H and subject to Seller's right to bring claims against
Amoco for a period of 120 days following the Closing Date based upon Seller's
due diligence evaluations pursuant to Section 4.4 of the Amoco Agreement, no
material portion of hydrocarbons produced from the Wells are subject to a gas
imbalance or other arrangement requiring delivery of hydrocarbons after the
Effective Date without receiving full payment therefor.

                 7.12     Leases.  To Seller's best knowledge, all royalties,
rentals and other payments due under the Leases have been properly and timely
paid except where the failure to





                                      -8-
<PAGE>   14
pay same will not have a material adverse effect on the value of the particular
Asset.  To Seller's best knowledge, subject to Seller's right to bring claims
against Amoco for a period of 120 days following the Closing Date based upon
Seller's due diligence evaluations pursuant to Section 4.2 of the Amoco
Agreement, all Leases are presently in full force and effect, and no written
notice of material default under any Lease has been received that could result
in cancellation of the Lease.  Any Lease which is not presently in full force
and effect, or for which all royalties, rentals or other payments due have not
been paid, or for which the lessee thereunder is in material default as of the
date of this Agreement shall be treated as a Defective Interest.  Buyer's
exclusive remedy for Seller's breach of this representation and warranty is set
forth in Section 12.3.

                 7.13     Operations in Progress.  Except for operations
disclosed on Exhibit I and normal daily operating expenses, as of the date of
this Agreement there are no operations in progress with respect to the Assets
which are reasonably expected to exceed $35,000 in cost net to Buyer's interest
and which shall be payable in whole or in part on or after the Effective Date.

                 7.14     Hydrocarbon Sales Contracts.  Except as specifically
indicated in Exhibit J and for calls on production, options to purchase or
similar rights with respect to production from the Wells, no material portion
of the hydrocarbons produced from the Wells is subject to a sales contract or
other agreement relating to the production, gathering, transporting,
processing, treating or marketing of hydrocarbons except those which can be
terminated upon not more than three months notice.

                 7.15     Proceeds of Production.  To Seller's best knowledge,
Buyer will be entitled to receive from all purchasers of production from the
Wells at least the NRI set forth in Exhibit B without suspense or any indemnity
other than the normal division order warranty of title, except where the
failure to receive same would not have a material adverse effect on the value
of the Assets.

                 7.16     Material Contracts.  To Seller's best knowledge, and
subject to the execution of new contracts in the ordinary course of business if
a contract has expired or has been terminated, all contracts material to the
Assets are in full force and effect (the "Material Contracts").  No written
notices of material default have been received regarding the Material Contracts
that remain uncured, or that Seller has not made provisions for under the Amoco
Agreement so that such event of default will not have a material adverse effect
on the Assets.

                 7.17     Bills in the Ordinary Course.  In the ordinary course
of business and to Seller's best knowledge, all costs and expenses pertaining
to the Assets have been timely paid, except where such payments are being
contested with good faith or except where the failure to make such payments
would not have a material adverse effect on the Assets.

                 7.18     Legal Proceedings.  Except as set forth on Exhibit K,
no suit, action or other proceeding is pending against Seller or, to Seller's
best knowledge, threatened in writing before any court, governmental agency,
arbitrator or other panel that relates to the Assets or the transaction
contemplated by this Agreement that might (i) impair the parties ability to
consummate the transaction contemplated by this Agreement or (ii) cause the
impairment or loss





                                      -9-
<PAGE>   15
of title to any material portion of the Assets or the value thereof, or (iii)
hinder or impede the operation or enjoyment of the Leases in any material
respect insofar as they relate to the Assets.

                 7.19     Compliance with Laws.  To Seller's best knowledge,
subject to Seller's right to bring claims against Amoco following the Closing
Date based upon Seller's due diligence evaluations pursuant to Sections 4.2
(claims within 120 days following the Closing Date) and 5.2 (claims within 180
days following the Closing Date) of the Amoco Agreement, all laws, rules,
regulations, ordinances and orders (of all governmental and regulatory bodies
having authority over the Assets) material to the operation of the Assets have
been complied with in all material respects.

                 7.20     Environmental Matters.  To Seller's best knowledge,
subject to Seller's right to bring claims against Amoco for a period of 180
days following the Closing Date based upon Seller's due diligence evaluations
pursuant to Section 5.2 of the Amoco Agreement, no conditions exist on the
Assets that would subject Buyer or any other party to any damages, remedial
action, injunctive relief or other liability under any Environmental Laws,
including without limitation, all costs associated directly or indirectly with
cleanup, removal, closure or other response actions; provided that Buyer or
such other party may be subject to such matters which are (i) routine in the
operation of the Assets and (ii) in the aggregate not material to the value of
the Assets as a whole.  All material permits, licenses and approvals affecting
the Assets and required under Environmental Laws have been obtained and the
Assets are in material compliance with such permits, licenses and approvals.

                 As used herein, the term "Environmental Laws" shall have the
meaning set forth in the Amoco Agreement and further shall include any and all
existing laws (common or statutory), rules, regulations, codes, or ordinances
issued or promulgated by any federal, state or local governmental entity
relating to the management and disposal of waste materials, the protection of
public or employee health and safety, the cleanup, remediation or prevention of
pollution, or the protection of the environment.

                 7.21     Payment of Taxes.  To Seller's best knowledge,
subject to Seller's right to bring claims against Amoco for a period of 120
days following the Closing Date based upon Seller's due diligence evaluations
pursuant to Section 4.2 of the Amoco Agreement, all ad valorem, property,
production, severance, excise and similar taxes and assessments based on or
measured by the ownership of property or the production of hydrocarbons or the
receipt of proceeds therefrom on the Assets which are currently due and payable
have been properly and timely paid, except to the extent such taxes are being
contested in good faith in the ordinary course of business.

                 7.22     Tax Partnerships.  Except as set forth in Exhibit L,
no portion of the Assets (i) has been contributed to and is currently owned by
a tax partnership; (ii) is subject to any form of agreement (whether formal or
informal, written or oral) deemed by any state or federal tax statute, rule or
regulation to be or to have created a tax partnership; or (iii) otherwise
constitutes "partnership property" (as that term is used throughout Subchapter
K of Chapter 1 of Subtitle A of the IRC) of a tax partnership.  Seller shall
retain all liability and responsibility, if any, to make all payments to
appropriate parties under the tax partnerships identified on Exhibit





                                      -10-
<PAGE>   16
L.  In addition to all other remedies available to Buyer, Seller shall
indemnify Buyer for all costs, losses, damages, penalties or expenses incurred
by Buyer as a result of any of the Assets having been contributed to or
currently owned by a tax partnership, and Buyer may elect, with a rebate in
accordance with the procedures of Section 12.3 and the provisions of Section
12.4, to reassign such Assets to Seller.  For purposes of this Section 7.22, a
"tax partnership" is any entity, organization or group deemed to be a
partnership within the meaning of IRC Section  761 or any similar state or
federal statute, rule or regulation, and that is not excluded from the
application of the partnership provisions of IRC Subchapter K of Chapter 1 of
Subtitle A and of all similar provisions of state tax statutes or regulations
by reason of elections made, pursuant to IRC Section  761(a) and all such
similar state or federal statutes, rules and regulations, to be excluded from
the application of all such partnership provisions.

                 7.23     Other Tax Matters.

                          (a)     NGPA Determination.

                                    (i)      Applications.  Except for the
         Wells listed on Exhibit M and subject to Seller's right to bring
         claims against Amoco for a period of 120 days following the Closing
         Date based upon Seller's due diligence evaluations pursuant to Section
         4.3 of the Amoco Agreement, all necessary filings have been made with
         the applicable state and federal agencies (the "Applications") for
         well determination(s) for each Well under the Natural Gas Policy Act
         of 1978, as amended (the "NGPA") and the rules and regulations of the
         Federal Energy Regulatory Commission (the "FERC") under such act (the
         "NGPA Regulations") requesting a determination that all or a
         quantifiable portion of the gas produced from a particular Well is
         "natural gas produced from designated tight formations" as defined in
         18 C.F.R. Section  274.205(e).  Each such application has been
         approved by the indicated state and federal agency and by the FERC and
         has been finally approved under and in accordance with Section 503 of
         the NGPA.  The Applications comply with the requirements of the NGPA
         and the NGPA Regulations and do not (1) contain any untrue statement
         of material fact or (2) omit any statement of material fact necessary
         to make the statements therein not misleading.  No further
         applications are required under the NGPA and the NGPA Regulations to
         allow the legal sale of all gas produced from the Wells at a price
         equal to the price for such gas currently being received.

                                    (ii)     Other Wells.  With respect to the
         Wells listed on Exhibit M, Part I identifies Wells which have been
         recompleted in accordance with private letter rulings issued by the
         Internal Revenue Service ("IRS") to third parties, or which have been
         or will be recompleted in an uphole formation in accordance with
         Situation 1 of Revenue Ruling 93-54 into a "qualifying formation"
         (tight formation or other qualifying formation) within the time frames
         set forth in subsection (b) below, and Part II identifies Wells
         drilled within the time frames set forth in subsection (b) below but
         no certificate was obtained from either the state agency or the FERC
         or both stating that the Well is qualified and Seller has a reasonable
         basis to believe that such a certificate could have been obtained if
         the state agency or the FERC were authorized to accept a





                                      -11-
<PAGE>   17
         request for such certificate.  With respect to all the Wells listed on
         Exhibit M, the hydrocarbons produced and sold from such Wells qualify
         for the Tax Credit.

                                    (iii)    Wells Where Commingling With
         Non-Qualified Production Is Conducted.  For Wells, if any, where
         production from a qualifying formation and production from a
         non-qualifying formation are commingled, the production has been
         allocated to each producing formation on a reasonable basis,
         consistent with industry standards and in accordance with procedures,
         if any, that have been approved by appropriate state and federal
         agencies.

                          (b)     Wells.  Each Well (1) has been timely drilled
under IRC Section  29(f)(1)(A) (drilled after December 31, 1979 but before
January 1, 1993), or administrative interpretations thereof, and (2) has been
timely drilled under IRC Section  29(c)(2)(B)(ii) or administrative
interpretations thereof, or Seller has a reasonable basis to believe that the
well was committed to interstate commerce (as defined in Section 2(18) of the
Natural Gas Policy Act of 1978, as in effect on November 5, 1990) as of April
20, 1977.

                          (c)     No Qualified Production prior to January 1,
1980.  Prior to January 1, 1980, there was no production of oil or gas from,
nor were any wells drilled or completed on, the "property" (within the meaning
of IRC Section  29) on which any Well is located nor was any portion of any
such "property" included within a unit from which oil or gas was produced or in
which any wells were drilled or completed prior to such date.

                           (d)    No Enhanced Oil Recovery Credit.  No oil or
gas produced from the Wells qualifies or has qualified for (i) the enhanced oil
recovery credit or any other credit under IRC Section  43 and none has been
claimed or taken on such oil or gas, or (ii) the credit allowed under IRC
Section  38 by reason of the energy percentage with respect to property used in
the project.

                          (e)     No Government Financing.  No portion of any
drilling, equipping, seismic or other development costs of the Assets were
financed by any state, local or federal agency, directly or indirectly,
including by way of grant, loan, expenditure or loan guaranty.

                          (f)     Seller Status.  Seller is not a non-resident
alien, foreign corporation, foreign partnership, foreign trust or foreign
estate (as those terms are defined in the IRC and the rules and regulations
promulgated thereunder), and Seller shall deliver to Buyer affidavits of
non-foreign ownership in the forms set forth in Exhibit N.

         8.      Certain Tax Matters.

                 8.1      Opinion of Tax Counsel, Right to Request Ruling.  At
Closing, Buyer at its sole cost, shall provide Seller a copy of the opinion
which Buyer has requested from Arthur Andersen LLP ("AA") regarding the tax
consequences of the transaction contemplated by this Agreement (the "Tax
Opinion").  Notwithstanding the Tax Opinion, Buyer shall have the right, but
not the obligation, to request a "private letter ruling" from the IRS to the
effect that (i) Buyer's interest in the Assets constitutes an economic interest
in minerals in place, and (ii) the Production Payment will be treated as a
mortgage loan under IRC Section  636 (a "Ruling").  Should





                                      -12-
<PAGE>   18
Buyer elect to request a Ruling, Buyer shall have no right to terminate or
rescind this Agreement if the Ruling is not acceptable to Buyer.  Seller shall,
in good faith, amend this Agreement and the documents contemplated hereunder in
order that Buyer may obtain a favorable Ruling, if, in Seller's sole and
reasonable discretion, such amendments will not have a material adverse effect
on Seller.

                 8.2      Tax Status.  Seller and Buyer intend that, for tax
purposes only, the Production Payment will be treated as a carved out
production payment under IRC Section  636(a) and as a mortgage loan and not as
an "economic interest" in the Assets.  Buyer shall have no recourse against
Seller in the event that the Production Payment is not so treated until the
commencement of a Tax Audit, in which event the provisions of Section 8.3 shall
control.

                 8.3      Escrow in the Event of Tax Audit.  Promptly following
the earlier to occur of (1) the date which is 90 days following receipt by a
member of Buyer of a notice from the IRS of the commencement of an
administrative proceeding at the partnership level pursuant to IRC Section
6223(a)(1) (a "Tax Audit"), or (2) the date of issuance by the IRS of either
(i) a notice of proposed adjustment with respect to any audit proceedings or
(ii) a so- called "60 day letter" (such earlier date, the "Escrow Commencement
Date"), Seller and Buyer shall enter into an Escrow Agreement with an escrow
agent, substantially in the form of Exhibit U; provided, however, that Buyer
may waive its rights to enter into such an Escrow Agreement, in which event the
provisions of Sections 8.3(a) through 8.3(d) shall not apply.  If Buyer does
not waive its rights to an Escrow Agreement, the Escrow Agreement and the funds
in the "Escrow Account" established pursuant thereto shall be administered in
accordance with the following provisions:

                          (a)     All Credit Payment Amounts which become
         payable after the Escrow Commencement Date, shall be deposited into
         the Escrow Account.  For tax purposes only, Buyer shall be treated as
         the owner of the escrow funds.

                          (b)     Buyer shall continue to deposit the Credit
         Payment Amounts in the Escrow Account until the conclusion of a Tax
         Audit.  The escrow funds in the Escrow Account shall be released at
         the conclusion of all ongoing Tax Audits.  A Tax Audit will be deemed
         to have concluded upon the earliest to occur of the following events:
         (i) the receipt by Buyer of written notice from the IRS that it will
         not assert any adjustments with respect to the transactions
         contemplated by this Agreement; (ii) Buyer entering into a settlement
         agreement with the IRS which resolves the open federal income tax
         issues in connection with such transactions; (iii) a judgment of a
         court of law or a decision in an administrative proceeding becoming
         non- appealable with respect to the open federal income tax issues in
         connection with such transactions; or (iv) the expiration of the
         applicable period of limitations for making assessments with respect
         to the years under examination in the Tax Audit if the IRS has made no
         assessments within such period with respect to such transactions.

                          (c)     Upon the event described in Section 8.3(b),
         Buyer shall receive from the escrow funds in the Escrow Account an
         amount, if any, equal to 70% of the total dollar amount of any
         reduction in Post-Audit Tax Credits resulting from a Tax Audit, plus
         interest on such amount at the rate applicable to the overpayment of
         tax.  For





                                      -13-
<PAGE>   19
         purposes of this Section 8.3(c), "Post-Audit Tax Credits" shall mean
         the Tax Credits associated with Credit Payment Amounts with respect to
         production and sales of Subject Hydrocarbons (as defined in the
         Production Payment Assignment) after the commencement of the Tax Audit
         and taking into account any reduction in tax credits resulting from
         the Tax Audit in question, and the amount of any reduction in
         Post-Audit Tax Credits resulting from a Tax Audit shall be determined
         without regard to the effect of such reduction upon Buyer's actual
         income tax liability.  Interest described in the initial sentence of
         this Section 8.3(c) shall run from the due date for Buyer's federal
         income tax return for the year that the Post-Audit Tax Credits in
         question were claimed.

                          (d)  Upon the conclusion of all ongoing Tax Audits,
         and the payment to Buyer of all amounts determined in accordance with
         Section 8.3(c), Seller shall receive the remaining amount of the
         escrow funds.

                 8.4      Settlements Resulting from a Tax Audit.  If Buyer
elects to enter into a negotiated settlement with the IRS of any Tax Audit
adjustments, Buyer shall, in good faith, consult with Seller regarding the
suggested terms of such settlement; provided, however, that Buyer shall be
under no obligation to comply with any suggestion of Seller.  Buyer shall
provide to Seller copies of all correspondence or pleadings between Buyer and
the IRS regarding any Tax Audit.  Seller shall be entitled to monitor all
hearings and meetings with the IRS associated with such settlement
negotiations.

         9.      Covenants.

                 9.1      Cooperation and Access.  Seller shall fully cooperate
with Buyer's post-Closing due diligence efforts, both at Seller's offices and
at the site of the Assets.  Seller shall promptly deliver to Buyer copies of
all evaluations and correspondence regarding Seller's due diligence and title
and environmental defect claims asserted under the Amoco Agreement.

                 9.2      Insurance.  At or prior to the Closing, Seller shall
cause Buyer to be named as an additional insured on all insurance policies
Seller has that pertain in any way to the ownership and operation of the
Assets.  At Closing, Seller will provide Buyer with Certificates of Insurance
naming Buyer as an additional insured, or other evidence, satisfactory to
Buyer, of compliance with this Section 9.2.

         10.     Closing Conditions.

                 10.1     Seller's Closing Conditions.  The obligation of
Seller to consummate the transactions contemplated hereby is subject, at the
option of Seller, to the satisfaction on or prior to the Closing Date of all of
the following conditions:

                          (a)     Representations, Warranties and Covenants.
         The (1) representations and warranties of Buyer contained in this
         Agreement shall be true and correct in all respects on and as of the
         Closing Date, and (2) covenants and agreements of Buyer to be
         performed on or before the Closing Date in accordance with this
         Agreement shall have been duly performed in all respects.





                                      -14-
<PAGE>   20
                          (b)     Closing Documents.  Buyer shall have executed
         and delivered the documents which are contemplated to be executed and
         delivered by it pursuant to Section 11 hereof prior to or on the
         Closing Date.

                          (c)     No Action.  On the Closing Date, no suit,
         action or other proceeding (excluding any such matter initiated by
         Seller or any of its affiliates) shall be pending or threatened before
         any court or governmental agency or body of competent jurisdiction
         seeking to enjoin or restrain the consummation of this Agreement or
         recover damages from Seller resulting therefrom.

                 10.2     Buyer's Closing Conditions.  The obligation of Buyer
to consummate the transactions contemplated hereby is subject, at the option of
Buyer, to the satisfaction on or prior to the Closing Date of all of the
following conditions:

                          (a)     Representations, Warranties and Covenants.
         The (1) representations and warranties of Seller contained in this
         Agreement shall be true and correct in all respects on and as of the
         Closing Date, and (2) covenants and agreements of Seller to be
         performed on or before the Closing Date in accordance with this
         Agreement shall have been duly performed in all respects.

                          (b)     Closing Documents.  Seller shall have
         executed and delivered the documents which are contemplated to be
         executed and delivered by it pursuant to Section 11 hereof prior to or
         on the Closing Date.

                          (c)     No Action.  On the Closing Date, no suit,
         action or other proceeding (excluding any such matter initiated by
         Buyer or any of its affiliates) shall be pending or threatened before
         any court or governmental agency or body of competent jurisdiction
         seeking to enjoin or restrain the consummation of this Agreement or
         recover damages from Buyer resulting therefrom.

                          (d)     Tax Opinion.  On or before the Closing Date,
         Buyer shall have received the Tax Opinion described in Section 8.1.

         11.     Closing.  The consummation of the transactions contemplated
hereby (the "Closing") shall occur, either in person or by facsimile, at the
offices of Davis, Graham & Stubbs LLP on the date of this Agreement (the
"Closing Date") or at such other time and place as the parties may agree to in
writing.  At Closing, the following events shall occur, each being a condition
precedent to the others and each being deemed to have occurred simultaneously
with the others (except where the documents involved indicate otherwise):

                 11.1     Advance.  Seller shall fund the Advance to Amoco on
behalf of Buyer.

                 11.2     Section 15.2 Payment.  Seller and Buyer shall pay to
the other, in cash or its equivalent, the amount due pursuant to Section 15.2,
if any, as reimbursement for the expenses incurred in connection with this
transaction.





                                      -15-
<PAGE>   21
                 11.3     Notice of Preferential Rights and Consents.  Seller
shall deliver to Buyer a copy of the notices sent to and any responses received
from third parties regarding preferential rights to purchase and consents
affecting the Assets with respect to the transactions contemplated by this
Agreement.

                 11.4     Assignments; Recourse Note; Option.  Seller and Buyer
shall execute and deliver the Wellbore Assignment, the Production Payment
Assignment, the Recourse Note and the Option.  In addition, Seller shall
prepare and Seller and Buyer shall execute such other conveyances on official
forms and related documentation necessary to transfer the Assets to Buyer in
accordance with requirements of governmental regulations; provided, however,
that any such separate or additional conveyances required pursuant to this
Section 11.4 or pursuant to Section 15.1 (i) shall evidence the conveyance and
assignment of the Assets and interests therein made or intended to be made in
the Wellbore Assignment and the Production Payment Assignment, (ii) shall not
modify or be deemed to modify any of the terms, reservations, covenants and
conditions set forth in the Wellbore Assignment or the Production Payment
Assignment, and (iii) shall be deemed to contain all of the terms, reservations
and provisions of the Wellbore Assignment or Production Payment Assignment, as
appropriate, as though the same were set forth at length in such separate or
additional conveyance.

                 11.5     Non-Foreign Ownership Affidavits.  Seller shall
deliver to Buyer the affidavits of non-foreign ownership substantially in the
forms set forth in Exhibit N, one stating that Seller is a non-foreign entity
for federal income tax purposes, and the other form stating that there is no
obligation for Colorado withholding tax under C.R.S.  Section  39-22-604.5.

                 11.6     Evidence of Insurance.  Seller shall provide Buyer
with certificates from Seller's insurers or other evidence that Buyer has been
named an additional insured on Seller's policies affecting the Assets.

                 11.7     Contribution Agreement.  Buyer shall deliver to
Seller the Contribution Agreement by and among Fontenelle, Inc. and Bald
Prairie, Inc. as members of Buyer, Buyer and Seller (as a third party
beneficiary), substantially in the form set forth in Exhibit O.

                 11.8     Guaranty Agreement.  Buyer shall deliver to Seller
the Guaranty Agreement from FMR Corp. in favor of Buyer as beneficiary and
Seller as third party beneficiary, substantially in the form set forth in
Exhibit O.

                 11.9  Seller's Officer's Certificate.  Seller shall execute
and deliver to Buyer the Officer's Certificate, substantially in the form
attached as Exhibit P.

                 11.10  Opinion on Behalf of Seller.  Seller shall deliver to
Buyer the opinion substantially in the form set forth in Exhibit Q.

                 11.11  Buyer's Manager's Certificate.  Buyer shall execute and
deliver to Seller the Manager's Certificate substantially in the form attached
as Exhibit R.





                                      -16-
<PAGE>   22
                 11.12  Opinion on Behalf of Buyer.  Buyer shall deliver to
Seller the opinion of Davis, Graham & Stubbs LLP, substantially in the form set
forth in Exhibit S.

                 11.13    Management Agreement.  Seller shall execute and
deliver to Buyer and Buyer shall execute and deliver to Seller the Management
Agreement (the "Management Agreement") and Memorandum of Management Agreement
and Power of Attorney substantially in the forms set forth in Exhibit T.

                 11.14    Performance Power of Attorney.  Buyer shall execute
and deliver to Seller counterparts of a Limited Power of Attorney,
substantially in the form of Exhibit V.

                 11.15    Tax Opinion.  Buyer shall deliver to Seller a copy of
the Tax Opinion of AA.

                 11.16    Additional Instruments.  Seller and Buyer shall
execute, acknowledge and deliver to each other such additional instruments as
are reasonable and customary to accomplish the purposes of this Agreement.

         12.     Post-Closing Matters.

                 12.1     Files and Records.  Following Closing, Seller shall
retain physical possession of all lease files, land files, division order
files, production marketing files and production records in Seller's possession
relating to the Assets (the "Records").  However, except to the extent that
Buyer's inspection thereof would violate legal constraints or legal
obligations, Buyer shall have the right to inspect the Records in Seller's
offices at any reasonable time.  At Buyer's request in writing (which written
request may be delivered by facsimile), to the extent that Seller's delivery
thereof would not violate legal constraints or legal obligations, Seller shall
make copies of the Records or materials in the Records at Seller's expense and
shall deliver said copies to Buyer at Seller's expense, provided that Seller
may charge Buyer the actual costs for such copies and delivery if such costs
exceed $250 per request.  If Buyer requires copies of the Records for its own
account, Seller will permit Buyer, at Buyer's own expense, to make copies of
pertinent material contained in the Records to the extent such action would not
violate legal constraints or legal obligations.

                 12.2     Sales Taxes and Recording Fees.  Seller shall be
responsible for making the payment to the proper authorities of all taxes and
fees occasioned by the sale of the Assets, including without limitation, any
transfer fees and sales taxes (which are to be apportioned one-half to Seller
and one-half to Buyer), and any documentary, filing and recording fees required
in connection with the filing and recording of any assignments or conveyances
delivered hereunder in the appropriate county, federal and/or state records.

                 12.3     Rebates for Defective Interests.  In addition to the
remedy provisions of Section 12.8, Buyer shall be entitled to the following
rebate if Seller does not have Defensible Title to the Assets.  At any time and
from time to time during the due diligence periods under the Amoco Agreement,
if Buyer discovers that Seller breached the representation and warranty set
forth in Sections 7.8, 7.12 or 7.20, Buyer may give Seller a Notice of
Defective Interests, which





                                      -17-
<PAGE>   23
notice shall describe the Defective Interest and the basis for the Defective
Interest.  Buyer shall be entitled to a rebate for a Defective Interest in the
amount of $3,197,000 multiplied by a fraction, the numerator of which is the
volume of reserves (net to Buyer) allocated to the Wells affected by the
Defective Interest and the denominator of which is the total volume of reserves
(net to Buyer) allocated to all of the Wells in the Reserve Report; provided,
however, that if the Defective Interest does not remain in effect during the
entire productive life of the subject Well, such fact shall be taken into
account in determining the amount of such rebate.

                 The rebate calculated above shall be paid from Seller to Buyer
if and only if the aggregate amount to be rebated with respect to all Defective
Interests exceeds a threshold of $35,000, and if such amount is exceeded, the
rebate shall be made for all Defective Interests.  In addition to any rebate on
account of Defective Interests, Buyer and Seller agree that all other express
dollar amounts, numbers or volumes set forth in this Agreement, the Production
Payment Assignment and Option, shall each be decreased, as appropriate, by
multiplying such amount or number, as the case may be, by a fraction, the
numerator of which is the aggregate volume of reserves associated with the
Assets without such Defective Interest and the denominator of which is the
total volume of reserves allocated to all of the Assets.

                 12.4     Rebates for Exercised Preferential Purchase Rights,
Failure to Obtain Consents.  If the holder of any preferential purchase right
exercises such right and the affected Asset cannot validly be conveyed to
Buyer, or if a required consent (except for Governmental Consents) to assign is
not obtained or deemed obtained within 45 days following Closing and the
affected Asset cannot be validly conveyed to Buyer, a portion of the amount set
forth in Section 12.3 shall be rebated for the value of such affected Asset and
such affected Asset shall be excluded from the Assets conveyed to Buyer
pursuant to the terms hereof (collectively the "Excluded Assets").  The amount
of the rebate for an Excluded Asset shall be determined in accordance with the
provisions of Section 12.3.  In addition to any rebate on account of Excluded
Assets, Buyer and Seller agree that all other express dollar amounts, numbers
or volumes set forth in this Agreement, the Production Payment Assignment and
Option, shall each be decreased, as appropriate, for the Excluded Assets in
accordance with the provisions of Section 12.3.

                 12.5     Reconveyance of Excluded Assets.  Seller shall
provide to Buyer, within 60 days following Closing, copies of all responses
from third parties regarding the notices sent to such third parties pursuant to
Section 11.3.  Upon written request from Seller, Buyer shall reconvey to
Seller, or Seller's designee, all Excluded Assets, free and clear of any
burdens, liens and encumbrances created by, through or under Buyer.

                 12.6     Allocation of Commingled Production and Costs.
Seller may have or acquire interests in the lands covered by the Leases that
are not part of the Assets ("Seller's Interests"), which are producing
hydrocarbons into a Well and such hydrocarbons are commingled with the
hydrocarbons produced from the Assets.  Seller and Buyer shall use reasonable
efforts to ensure that hydrocarbon production from the Wells is allocated
between Seller's Interests and the Assets on a reasonable basis, consistent
with industry standards and in accordance with procedures, if any, that have
been approved by appropriate state and federal agencies.  Costs and expenses
shall be allocated between the Seller's Interests and the Assets in





                                      -18-
<PAGE>   24
accordance with the allocation of production between the Seller's Interests and
the Assets; provided that costs and expenses directly attributable to Seller's
Interests shall be allocated to such Seller's Interests, and costs and expenses
directly attributable to the Assets shall be allocated to and debited against
the Net Profits Account under the Production Payment Assignment.

                 12.7     Performance of Buyer.  Seller shall be entitled to
the remedy of specific performance of Buyer's obligations under this Agreement
and the other documents contemplated hereunder in order to be assured of the
benefits contemplated under this Agreement, the Production Payment Assignment,
Option or Management Agreement.  Should Buyer fail to perform any obligation
under this Agreement, the Production Payment Assignment, Option or Management
Agreement, which if unremedied would have a material adverse effect on Seller,
then Seller may give written notice to Buyer of such failure to perform.  If
Seller gives such notice and Buyer does not remedy such failure within 60 days
of receipt of such notice, in addition to the remedy of specific performance,
Seller shall have the right to cause the attorney-in-fact of Buyer identified
in the Limited Power of Attorney to execute an Assignment, Bill of Sale and
Conveyance in a form substantially similar to that set forth in Exhibit V
covering any or all of the Assets which are adversely affected by such failure.
Seller and Buyer expressly waive any and all claims against the
attorney-in-fact named in the Limited Power of Attorney and any right to enjoin
such attorney-in-fact.

                 12.8     Overpayments.  If at any time Buyer is determined to
have paid Seller more than the amount then due with respect to any Credit
Payment Amount, then as Buyer's exclusive remedy, Seller shall be obligated to
return any such overpayment, limited to amounts actually paid to Seller by
Buyer, after Buyer notifies Seller of the amount of such overpayment and
provides Seller substantiation thereof.  Alternatively, without limiting
Buyer's recourse under the preceding sentence, Buyer may elect to offset the
amount of any such overpayment against future Credit Payment Amounts.

         13.     Apportionment of Liabilities and Obligations.

                 13.1     Buyer.  Upon Closing, Buyer shall assume and pay for
all costs, expenses, liabilities and obligations accruing or relating to the
owning, operating or maintaining of the Assets or the producing, transporting
and marketing of hydrocarbons from the Assets, relating to periods on and after
the Effective Date, including without limitation, environmental obligations and
liabilities, off-site liabilities associated with the Assets, the obligation to
plug and abandon all Wells and reclaim all Well sites and all obligations
arising under agreements covering or relating to the Assets (collectively, the
"Post-Effective Date Liabilities").

                 13.2     Seller.  Upon Closing, Seller shall retain, assume
and pay for all costs, expenses, liabilities and obligations accruing or
relating to the owning, operating or maintaining of the Assets or the
producing, transporting and marketing of hydrocarbons from the Assets, relating
to periods before the Effective Date, including without limitation,
environmental obligations and liabilities, the obligation to plug and abandon
wells (to the extent relating to periods prior to the Effective Date), off site
liabilities associated with the Assets, and all obligations arising under
agreements covering or relating to the Assets (collectively, the "Pre-Effective
Date Liabilities").





                                      -19-
<PAGE>   25
         14.     Indemnification.  For the purposes of this Agreement, "Losses"
shall mean any actual loss, cost and expense (including reasonable fees and
expenses of attorneys, technical experts and expert witnesses), liability, and
damage (including those arising out of demands, suits, sanctions of every kind
and character); provided, however, that in no event shall "Losses" be deemed to
include consequential damages of a party to this Agreement.

                 14.1     Buyer's Indemnification of Seller.  Subject to the
terms of and the indemnification obligations contained in the Management
Agreement, Buyer shall indemnify and hold harmless Seller, its officers,
directors, shareholders, employees, representatives, agents, successors and
assigns, forever, from and against all Losses and interest thereon which arise
from or in connection with (i) the Post-Effective Date Liabilities, and (ii)
Buyer's breach of its representations, warranties and covenants in this
Agreement.

                 14.2     Seller's Indemnification of Buyer.  Subject to the
terms of and the indemnification obligations contained in the Management
Agreement, Seller shall indemnify and hold harmless Buyer; its officers;
directors; members; employees; representatives; agents; successors and assigns;
and the employees, representatives, agents, successors and assigns of such
members forever, from and against all Losses and interest thereon which arise
from or in connection with (i) the Pre-Effective Date Liabilities, and (ii)
Seller's breach of its representations, warranties and covenants in this
Agreement regardless of Seller's knowledge if such representations or
warranties are knowledge qualified, provided that the matters contemplated in
this clause (ii) shall not apply to the representations set forth in Section
7.6 or matters with respect to which this Agreement expressly provides an
exclusive remedy under Section 12.8.  Buyer and Seller shall cooperate fully
and consult in good faith with each other in the litigation of any matter
identified in this Section 14.2.

         Notwithstanding any of the foregoing provisions of this Section 14.2,
Buyer shall be entitled to payment for matters indemnified under this Section
14.2 only after a court of competent jurisdiction makes a final determination
regarding the matter litigated; provided that such payment shall cover only
Losses incurred by Buyer which have not been remedied by Seller under the
escrow provisions of Section 8.3 above and/or the overpayment provisions of
Section 12.8 above.

                 14.3     Third Party Claims.  If a claim by a third party is
made against Seller or Buyer (an "Indemnified Party"), and if such party
intends to seek indemnity with respect thereto under this Section 14, such
Indemnified Party shall promptly notify Buyer or Seller, as the case may be
(the "Indemnitor"), of such claim.  The Indemnitor shall have 30 days after
receipt of such notice to undertake, conduct and control, through counsel of
its own choosing and at its own expense, the settlement or defense thereof, and
the Indemnified Party shall cooperate with it in connection therewith; provided
that the Indemnitor shall permit the Indemnified Party to participate in such
settlement or defense through counsel chosen by such Indemnified Party,
however, the fees and expenses of such counsel shall be borne by such
Indemnified Party.  So long as the Indemnitor, at its cost and expense, (1) has
undertaken the defense of, and assumed full responsibility for all Losses with
respect to, such claim, and (2) is reasonably contesting such claim in good
faith, by appropriate proceedings, the Indemnified Party shall not pay or
settle any





                                      -20-
<PAGE>   26
such claim.  Notwithstanding compliance by the Indemnitor with the preceding
sentence, the Indemnified Party shall have the right to pay or settle any such
claim, provided that in such event it shall waive any right to indemnity
therefor by the Indemnitor for such claim.  If, within 30 days after the
receipt of the Indemnified Party's notice of a claim of indemnity hereunder,
the Indemnitor does not notify the Indemnified Party that it elects, at
Indemnitor's cost and expense, to undertake the defense thereof and assume full
responsibility for all Losses with respect thereto, or gives such notice and
thereafter fails to contest such claim in good faith, the Indemnified Party
shall have the right to contest, settle or compromise the claim but shall not
thereby waive any right to indemnity therefor pursuant to this Agreement.

         15.     Miscellaneous.

                 15.1     Further Assurances.  After Closing, Seller and Buyer
shall execute, acknowledge and deliver or cause to be executed, acknowledged
and delivered such instruments and take such other action as may be reasonably
necessary or advisable to carry out the purposes and intents of this Agreement
and any document, certificate or other instrument delivered pursuant hereto.

                 15.2     Expenses.  Seller and Buyer each agree to pay
one-half of the reasonable costs and expenses of Arthur Andersen LLP and Davis,
Graham & Stubbs LLP incurred in connection with this transaction, subject to
receipt of evidence and substantiation thereof.  Such costs and expenses shall
not include any costs or expenses associated with the Tax Opinion.  Seller and
Buyer shall pay their respective amount of taxes and fees, apportioned to each
under Section 12.2.

                 15.3     Notices.  All notices under this Agreement shall be
in writing and addressed as set forth below.  Any communication or delivery
hereunder shall be deemed to have been duly made and the receiving party
charged with notice (i) if personally delivered or telecopied, when received,
(ii) if mailed, three business days after mailing, certified mail, return
receipt requested, or (iii) if sent by overnight courier, one day after
sending.  All notices shall be addressed as follows:

                 If to Seller:

                 HS Resources, Inc.
                 1999 Broadway, Suite 3600
                 Denver, Colorado  80202
                 Attn:  General Counsel
                 Telephone: (303) 296-3600
                 Fax:  (303) 296-3601





                                      -21-
<PAGE>   27
                 If to Buyer:

                 WestTide Investments, LLC
                 c/o FMR Corp.
                 82 Devonshire Street, R22C
                 Boston, Massachusetts  02109
                 Attention: Roger D. Tullberg
                 Telephone: (617) 563-4791
                 Fax:  (617) 476-6248

                 with a copy to:

                 Sullivan & Worcester
                 One Post Office Square
                 Boston, Massachusetts  02109
                 Attention: Christopher C. Curtis, Esq.
                 Telephone: (617) 338-2839
                 Fax:  (617) 338-2880

Any party may, by written notice so delivered to the other party, change the
address or individual to which delivery shall thereafter be made.

                 15.4     Survival.  The representations, warranties,
covenants, agreements and indemnities included or provided in this Agreement
shall survive the Closing.  The doctrine of merger shall not cause any
representation, warranty, covenant, agreement or indemnity under this Agreement
to terminate as a result of Buyer and Seller entering into the Wellbore
Assignment, Production Payment Assignment, Option or any other instrument
contemplated hereunder.

                 15.5     Confidentiality.  Buyer and Seller shall keep this
Agreement confidential except to the extent each may be required to disclose
the contents hereof by recording the Wellbore Assignment, Production Payment
Assignment, Option, and Memorandum of Management Agreement and Power of
Attorney in the real property records in the counties where the Assets are
located or filing the official forms of conveyances covering the Assets with
appropriate governmental authorities, the IRS or to the extent required in the
operation of the Assets, pursuant to the Management Agreement, by law,
regulation or order, in connection with obtaining third party consents and
waivers of preferential purchase rights and other matters, or in connection
with any public announcement issued in accordance with Section 15.6 hereof.

                 15.6     Announcements.  Seller and Buyer shall consult with
each other regarding all press releases and other public announcements issued
at, prior to or following Closing concerning this Agreement or the transactions
contemplated hereby and except as may be required by applicable laws or the
applicable rules and regulations of any governmental agency or stock exchange.
Neither Buyer nor Seller shall issue any such press release or other public
announcement without the prior written consent of the other party, which
consent will not be unreasonably withheld.  In all such press releases and
other public announcements, Seller shall refer to Buyer as being affiliated
with a large east coast financial institution.





                                      -22-
<PAGE>   28
                 15.7     Assignment.  Neither Buyer nor Seller may assign its
rights or delegate its duties or obligations under the terms of this Agreement
without the prior written consent of the other party, provided that either
Buyer or Seller may assign its rights, but not its obligations under this
Agreement, to any party (including any affiliated or nonaffiliated party) as
long as such assignment does not relieve the assigning party of its obligations
to the other party hereto, and provided further that Buyer may not cause or
permit an assignment, transfer, sale, alienation or other disposition of all or
any portion of the Assets which would result in the transferred Assets becoming
"plan assets" under the Employee Retirement Income Security Act of 1974, as
amended.

                 15.8     Binding Effect.  This Agreement shall be binding upon
and shall inure to the benefit of the parties hereto and their successors and,
subject to Section 15.7 hereof, their assigns.

                 15.9     Complete Agreement.  When executed by the authorized
representative of Seller and Buyer, this Agreement, the Exhibits hereto and the
documents to be delivered pursuant hereto shall constitute the complete
agreement between the parties.  This Agreement may be amended only by a writing
signed by both parties.

                 15.10    Knowledge.  As used in this Agreement, the term
"knowledge," "best knowledge" or any variations thereof shall mean the actual
knowledge of any fact, circumstance or condition by the officers or employees
at a manager or higher level of the party involved as such knowledge has been
obtained in the performance of their duties in the ordinary course of business
after making reasonable and appropriate inquiries.

                 15.11    Governing Law.  THIS AGREEMENT SHALL BE GOVERNED BY
AND CONSTRUED IN ACCORDANCE WITH THE LAW OF THE STATE OF COLORADO WITHOUT
REFERENCE TO THE CONFLICT OF LAW PROVISIONS THEREOF.

                 15.12    Counterparts.  This Agreement may be executed in one
or more counterparts, all of which shall be considered one and the same
agreement, and shall become effective when one or more counterparts have been
signed by each party and delivered to the other party.





                                      -23-
<PAGE>   29
         EXECUTED as of the date first above mentioned.

                                           BUYER:

                                           WESTTIDE INVESTMENTS, LLC
                                           By: Its Manager, Fontenelle, Inc.


                                           By:
                                              ----------------------------
                                              Gary L. Greenstein
                                              Vice President

                                           SELLER:

                                           HS RESOURCES, INC.



                                           By:
                                              ----------------------------
                                              George H. Solich
                                              Vice President Acquisitions &
                                                Divestitures





                                      -24-
<PAGE>   30
STATE OF COLORADO           )
   CITY AND                 ) ss.
COUNTY OF DENVER            )

         The foregoing instrument was acknowledged before me this 11th day of
December, 1997, by George H. Solich, as Vice President Acquisitions &
Divestitures of HS Resources, Inc., a Delaware corporation, on behalf of such
corporation.

         Witness my hand and official seal.


                                  ----------------------------
                                  Notary Public

                                  My commission expires:
                                                         ------------
(SEAL)



STATE OF COLORADO          )
   CITY AND                ) ss.
COUNTY OF DENVER           )

         The foregoing instrument was acknowledged before me this 15th day of
December, 1997 by Gary L. Greenstein, Vice President of Fontenelle, Inc., a
Delaware corporation, Manager of WestTide Investments, LLC, a Delaware limited
liability company on behalf of the company.

         Witness my hand and official seal.

                                  ----------------------------
                                  Notary Public

                                  My commission expires:
                                                          -----------
(SEAL)





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