Document:

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                                                                    EXHIBIT 10.2

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                            STOCK PURCHASE AGREEMENT

                                  BY AND AMONG

                            BILL BARRETT CORPORATION

                                       AND

              THE PARTIES LISTED ON ANNEX A HERETO AS ITS INVESTORS

                           DATED AS OF MARCH 28, 2002

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                                TABLE OF CONTENTS

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<S>                   <C>                                                                               <C>
ARTICLE I PURCHASE AND SALE OF SHARES................................................................... 1
     Section 1.1      Series B Preferred Stock.......................................................... 1
     Section 1.2      Purchase Of Initial Shares........................................................ 2
     Section 1.3      Purchase Price.................................................................... 2
     Section 1.4      Purchase of Series A Preferred Stock ("Series A Preferred")....................... 2

ARTICLE II CLOSING ..................................................................................... 2
     Section 2.1      Closing........................................................................... 2
     Section 2.2      Deliveries By The Company......................................................... 2
     Section 2.3      Deliveries By The Investors....................................................... 3

ARTICLE III FINANCIAL COMMITMENT........................................................................ 4
     Section 3.1      Agreement To Purchase Additional Shares........................................... 4
     Section 3.2      Investor Call Right To Purchase Shares............................................ 6
     Section 3.3      Early Termination Of The Takedown Period.......................................... 7
     Section 3.4      Rights Of Investors............................................................... 8
     Section 3.5      No Commitment For Additional Financing............................................ 8
     Section 3.6      Exculpation Among Investors....................................................... 9

ARTICLE IV NON-PARTICIPATION; EVENT OF DEFAULT.........................................................  9
     Section 4.1      Non-Participation By An Investor.................................................  9
     Section 4.2      Default By An Investor........................................................... 10
     Section 4.3      Loss Of Certain Rights........................................................... 11

ARTICLE V REPRESENTATIONS AND WARRANTIES OF THE COMPANY................................................ 11
     Section 5.1      Organization; Good Standing; Qualification....................................... 11
     Section 5.2      Capitalization And Voting Rights................................................. 12
     Section 5.3      Subsidiaries..................................................................... 13
     Section 5.4      Authorization.................................................................... 13
     Section 5.5      Valid Issuance Of Series B Preferred And Common Stock............................ 14
     Section 5.6      Offering......................................................................... 14
     Section 5.7      Consents......................................................................... 14
     Section 5.8      Compliance With Other Instruments................................................ 15
     Section 5.9      Compliance With Laws............................................................. 15
     Section 5.10     Environmental Matters............................................................ 15
     Section 5.11     Related Party Transactions....................................................... 16
     Section 5.12     Registration Rights.............................................................. 17
     Section 5.13     Title To Property And Assets..................................................... 17
     Section 5.14     Employees; Employee Compensation................................................. 17
     Section 5.15     Tax Matters...................................................................... 18
     Section 5.16     Minute Books..................................................................... 18
     Section 5.17     Investment Company Act........................................................... 18
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<S>                   <C>                                                                              <C>
     Section 5.18     No Prior Activities.............................................................. 19
     Section 5.19     Litigation....................................................................... 20
     Section 5.20     Certain Agreements Of Officers And Employees..................................... 20
     Section 5.21     Brokers.......................................................................... 20
     Section 5.22     Financial Statements............................................................. 20
     Section 5.23     Disclosure....................................................................... 21

ARTICLE VI REPRESENTATIONS AND WARRANTIES OF THE INVESTORS............................................. 21
     Section 6.1      Authorization.................................................................... 21
     Section 6.2      Purchase Entirely For Own Account................................................ 22
     Section 6.3      Reliance Upon Investors' Representations......................................... 22
     Section 6.4      Receipt Of Information........................................................... 22
     Section 6.5      Investment Experience............................................................ 23
     Section 6.6      Accredited Investor.............................................................. 23
     Section 6.7      Restricted Securities............................................................ 23
     Section 6.8      Litigation....................................................................... 23
     Section 6.9      Brokers Or Finders............................................................... 24
     Section 6.10     Jurisdiction Of Organization..................................................... 24

ARTICLE VII ADDITIONAL AGREEMENTS...................................................................... 24
     Section 7.1      Confidentiality.................................................................. 24
     Section 7.2      Public Announcements............................................................. 25
     Section 7.3      Fees And Expenses................................................................ 25
     Section 7.4      Use Of Proceeds.................................................................. 25
     Section 7.5      Reincorporation in Delaware...................................................... 26
     Section 7.6      Amended and Restated 2002 Stock Option Plan...................................... 26

ARTICLE VIII SURVIVAL OF REPRESENTATIONS; INDEMNIFICATION.............................................. 26
     Section 8.1      Survival of Representations...................................................... 26
     Section 8.2      Agreement to Indemnify........................................................... 27
     Section 8.3      Limitation of Liability.......................................................... 27
     Section 8.4      Conditions of Indemnification.................................................... 28

ARTICLE IX MISCELLANEOUS .............................................................................. 28
     Section 9.1      Notices.......................................................................... 28
     Section 9.2      Entire Agreement................................................................. 29
     Section 9.3      Binding Effect; Assignment; No Third Party Benefit............................... 29
     Section 9.4      Severability..................................................................... 30
     Section 9.5      California Corporate Securities Law.............................................. 30
     Section 9.6      Governing Law.................................................................... 30
     Section 9.7      Descriptive Headings............................................................. 30
     Section 9.8      Gender........................................................................... 31
     Section 9.9      References....................................................................... 31
     Section 9.10     Injunctive Relief................................................................ 31
     Section 9.11     Consent To Jurisdiction.......................................................... 31

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<S>                   <C>                                                                              <C>
     Section 9.12     Amendment........................................................................ 32
     Section 9.13     Effect Of Amendment Or Waiver.................................................... 32
     Section 9.14     Waiver........................................................................... 32
     Section 9.15     Counterparts..................................................................... 32
     Section 9.16     Adjustments for Stock Splits, Etc................................................ 33

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                            SERIES B PREFERRED STOCK

                               PURCHASE AGREEMENT

          THIS SERIES B PREFERRED STOCK PURCHASE AGREEMENT (this "Agreement") is
made and entered into this 28th day of March, 2002, by and among Bill Barrett
Corporation, a Maryland corporation (the "Company"), and each of the parties
listed on Annex A attached hereto, each of which is herein referred to as an
"Investor" and all of whom are collectively referred to as "Investors."

                                   WITNESSETH:

          WHEREAS, the Board of Directors of the Company has approved the sale
and issuance of an aggregate of up to 51,000,000 shares of its Series B
Preferred Stock, par value $.001 per share (the "Series B Preferred");

          WHEREAS, each Investor desires to purchase such number of shares of
Series B Preferred as set forth opposite such Investor's name on Annex A under
the column designated "total shares" (collectively, the "Shares");

          WHEREAS, upon the terms and subject to the conditions of this
Agreement, the Company desires to sell and each Investor desires to purchase at
the Closing (as defined below) the portion of the Shares set forth opposite such
Investor's name on Annex A under the column designated "initial shares"
(collectively, the "Initial Shares"); and

          WHEREAS, the Company desires to enter into this Agreement for the
purpose of setting forth all of the terms, limitations and conditions pursuant
to which (i) the Investors shall purchase, and the Company shall be required to
issue and sell, the Initial Shares, and (ii) each Investor has made a binding
obligation to purchase additional shares of Series B Preferred, in each case,
subject to the terms and conditions as set forth herein.

          NOW, THEREFORE, for and in consideration of the foregoing and the
respective representations, warranties, covenants, agreements and conditions set
forth herein, the parties agree as follows:

                                   ARTICLE I

                           PURCHASE AND SALE OF SHARES

          SECTION 1.1 SERIES B PREFERRED STOCK.

          The Company shall adopt and file with the Secretary of State of the
State of Maryland on or before the Closing (as defined below) an Amended and
Restated Articles of Incorporation in the form attached hereto as Exhibit A (the
"Restated Articles") and Articles Supplementary Series B Preferred Stock
attached hereto as Exhibit B (the "Series B Articles Supplementary").

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          SECTION 1.2 PURCHASE OF INITIAL SHARES.

          At the Closing and on the terms and subject to the conditions set
forth in this Agreement, the Company shall authorize, issue and sell to each
Investor in consideration of the Purchase Price (as defined in Section 1.3), and
each Investor, severally and not jointly, shall purchase the number of shares of
the Initial Shares as set forth opposite such Investor's name on Annex A. Each
Investor shall make payment therefor by wire transfer to a bank account
designated by the Company in writing to each Investor prior to the Closing.

          SECTION 1.3 PURCHASE PRICE.

          The purchase price for each share of Series B Preferred to be
purchased by each Investor pursuant to the terms hereof, whether at the Closing
or pursuant to any Capital Call (as defined below), shall be equal to $5.00 per
share (the "Purchase Price").

          SECTION 1.4 PURCHASE OF SERIES A PREFERRED STOCK ("SERIES A
PREFERRED").

          On or prior to 14 days from the date hereof, the Company shall
complete the offering and sale of 6,139,089 shares of Series A Preferred for
cash at a price of $4.17 per share. The aggregate purchase price for all such
shares of Series A shares shall not exceed $25,600,000, and at least 1,846,523
Series A Preferred shall have been purchased by the officers and key employees
of the Company listed on Annex B (the "Management Stockholders"). In addition,
up to 305,276 shares of Series A Preferred may be issued on or before July 31,
2002 as a portion of the consideration for the purchase of an option and
potential leasing of certain land described in Section 5.18(v) and up to 455,635
shares of Series A Preferred may be issued upon the conversion of the
convertible promissory note described in Section 5.18(vi).

                                   ARTICLE II

                                     CLOSING

          SECTION 2.1 CLOSING.

          The purchase and sale of the Initial Shares shall take place
simultaneously with the execution of this Agreement at the Company's offices at
1099 18th Street, Suite 2300, Denver, Colorado 80202, at 10:00 a.m., on March
28, 2002, or at such other time and place as the Company and the Investors shall
mutually agree, either orally or in writing (which time and place are designated
as the "Closing").

          SECTION 2.2 DELIVERIES BY THE COMPANY.

          Subject to the terms and conditions hereof, at the Closing, the
Company will deliver the following to each Investor:

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                  (a) A certificate representing the number of Initial Shares
being purchased by such Investor at the Closing;

                  (b) A counterpart of the Registration Rights Agreement, in
substantially the form set forth as Exhibit C (the "Registration Rights
Agreement"), duly executed by the Company;

                  (c) A counterpart of the Stockholders' Agreement, in
substantially the form set forth as Exhibit D (the "Stockholders' Agreement"),
duly executed by the Company;

                  (d) Evidence that the Restated Articles and the Series B
Articles Supplementary have been filed with the Secretary of State of the State
of Maryland and such Restated Articles and the Series B Articles Supplementary
have become effective;

                  (e) An opinion of Patton Boggs, LLP, counsel for the Company,
dated as of the date of the Closing, in the form attached hereto as Exhibit E;

                  (f) Evidence that the Company's Board of Directors has
authorized the transactions contemplated by this Agreement, the increase in size
of the Company's Board to eight directors; evidence of the resignation from the
Board of Directors of Robert Howard; and evidence of the appointment to the
vacancies on the Board of Directors of Jeffrey A. Harris, as designee of Warburg
Pincus Private Equity VIII, L.P., Henry Cornell, as designee of GS Capital
Partners 2000, L.P., and Christopher Behrens, as designee of J.P. Morgan
Partners (BHCA), L.P. (the "Investor Appointees") and an independent director to
be appointed in accordance with the Stockholders' Agreement; and

                  (g) A letter regarding management rights, in substantially the
form set forth as Exhibit F, duly executed by the Company;

                  (h) A letter regarding regulatory compliance (the "Regulatory
Side Letter") in substantially the form set forth as Exhibit G, duly executed by
the Company; and

                  (i) All other documents, instruments and writings reasonably
required to be delivered by the Company at or prior to the Closing pursuant to
this Agreement.

          SECTION 2.3 DELIVERIES BY THE INVESTORS.

          Subject to the terms and conditions hereof, at the Closing, each
Investor is severally and not jointly obligated to deliver the following to the
Company:

                  (a) The Purchase Price payable by such Investor for the
Initial Shares reflected next to such Investor's name on Annex A;

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                  (b) A counterpart of the Registration Rights Agreement, duly
executed by such Investor;

                  (c) A counterpart of the Stockholders' Agreement, duly
executed by such investor;

                  (d) A counterpart of the Regulatory Side Letter signed by J.P.
Morgan Partners (BHCA), L.P.; and

                  (e) All other documents, instruments and writings reasonably
required to be delivered to the Company by such Investor at or prior to the
Closing pursuant to this Agreement.

                                  ARTICLE III

                              FINANCIAL COMMITMENT

          SECTION 3.1 AGREEMENT TO PURCHASE ADDITIONAL SHARES.

                  (a) Set forth opposite each Investor's name on Annex A, under
the column designated "Total Shares", is the maximum aggregate number of shares
of Series B Preferred that such Investor hereby commits to purchase at the
Purchase Price upon and pursuant to validly instituted Capital Calls (as defined
below) by the Company and subject to the terms, limitations and conditions of
this Agreement. The aggregate Purchase Price payable for the total shares to be
purchased by such Investor pursuant to Capital Calls represents such Investor's
"Total Commitment." The "Remaining Commitment" means as to any Investor, at any
time, an amount equal to such Investor's Total Commitment at such time reduced
by the sum of the Purchase Price paid by such Investor at the Closing and
pursuant to validly instituted Capital Calls by the Company pursuant to and
subject to the terms of this Section 3.1. During the time period commencing on
the Closing and continuing until the earlier to occur of: (i) the fifth
anniversary of the Closing, (ii) the date on which the Remaining Commitment of
all Investors is zero, or (iii) such earlier date as provided in Section 3.3
(such time period, the "Takedown Period"), upon 20 business days' prior written
notice from the Company substantially in the form of Exhibit H hereto (each, a
"Call Notice") (unless all of the Investors have waived in writing such 20
business-day period), the Company may require (subject to the terms, limitations
and conditions of this Agreement (including Section 4.1 hereof), the Company's
authority and Board of Director approval procedures set forth in the Bylaws of
the Company) the Investors to purchase additional shares of Series B Preferred
from the Company (each, a "Capital Call") for the purposes described in Section
7.4 hereof. Each Capital Call shall be apportioned ratably among the aggregate
Remaining Commitments of all Investors. The amount called for from a particular
Investor pursuant to a Capital Call may not exceed such Investor's Remaining
Commitment.

                  (b) All Capital Calls shall be approved by the Company's Board
of Directors, including a majority of the Directors who are Investor Appointees

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appointed in accordance with the terms of the Stockholders' Agreement at which
time the Company shall provide to the Investor Appointees a draft Call Notice
substantially complete to the best of the Company's knowledge. All Capital Calls
shall be in an aggregate minimum amount of at least $5,000,000. The Company
shall attempt to manage the number of Capital Calls from the Investors in such a
manner so that no more than one call is made during a particular calendar
quarter; provided, however, that notwithstanding such attempts, Capital Calls
may occur as often as necessary. No Capital Call will be valid without the prior
written consent of the Investors holding 60% or more of the shares of Series B
Preferred then outstanding if at the time such Call Notice is provided (A) the
Company or any subsidiary is in default (i) under its repayment obligations
arising from a debenture, promissory note or similar instrument evidencing
funded indebtedness of the Company or any subsidiary, or (ii) under payment
obligations arising under any purchase money indebtedness or capital lease
obligations totaling in excess of $10,000,000; or (B) the Call Notice is
materially different from, or makes disclosures which are materially different
from those set forth in, the draft Call Notice provided to the Investor
Appointees at the time the Capital Call was approved.

                  (c) Each Capital Call for funding shall be accompanied by (i)
a Call Notice and shall specify in reasonable detail the purpose of such capital
contributions and shall specify the number of shares of Series B Preferred to be
acquired by each Investor (which number shall equal its pro rata portion of the
Capital Call based on its Remaining Commitment divided by the Purchase Price);
and (ii) if reasonably requested by a majority of the Investor Appointees, an
opinion of counsel as to federal securities law compliance. No Investor shall
have any right to decline to purchase the shares of Series B Preferred described
in such Capital Call if such Capital Call has been made in accordance with this
Agreement and the Bylaws of the Company, except as otherwise expressly provided
in Section 4.1 hereof.

                  (d) Each Call Notice shall set forth the date on which the
purchase and sale of the Series B Preferred shall take place pursuant to such
Capital Call (the "Contribution Date"), which date shall be no earlier than the
21st business day following the date of the Call Notice.

                  (e) If requested to do so at least five days prior to the
designated Contribution Date, the Company shall delay the Contribution Date with
respect to an Investor (which delay shall not apply to other Investors not
invoking this Section 3.1(e)) to allow the Company and any Investor that
delivers a written opinion of counsel (if requested by the Company) reasonably
acceptable to the Company to the effect that such Investor must make a required
governmental filing in connection with such Capital Call to make such required
governmental filing (provided that such Investor shall make such required
governmental filing as promptly as possible), for the expiration of
governmentally imposed waiting periods and the obtaining of governmental
approvals, pursuant to the Hart-Scott-Rodino Anti-Trust Improvements Act of
1976, as amended, if any; provided, however, that any Investor may waive the
requirements of this Section 3.1(e) in writing at the time of such Capital Call
with respect to such Investor.

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                  (f) On each Contribution Date, (i) the Company shall deliver
to the Investors who are acquiring shares of Series B Preferred, an Officer's
Certificate in substantially the form set forth in Exhibit I, (ii) each Investor
(other than a Non-Participating Investor) shall acquire the number of shares of
Series B Preferred specified in the Call Notice and shall make payment therefor
by wire transfer to a bank account designated by the Company, and (iii) the
Company shall immediately deliver to such Investor a certificate representing
the shares of Series B Preferred that such Investor is purchasing pursuant to
such Capital Call.

                  (g) Subject to Section 9.3 of this Agreement, each Investor
shall have the right to transfer its Shares in accordance with the Stockholders'
Agreement; provided, however, that no such assignment shall relieve any such
assignor from its remaining liabilities and obligations under this Agreement
unless approved by the Board of Directors of the Company, which approval shall
not be unreasonably withheld.

          SECTION 3.2 INVESTOR CALL RIGHT TO PURCHASE SHARES.

                  Upon the affirmative vote of the Investors holding 60% or more
of the outstanding shares of Series B Preferred, each Investor will have the
right, but not the obligation (the "Investor Call Right"), prior to the
termination of the Takedown Period, to purchase at the Purchase Price each such
Investor's pro rata share of the number of shares of Series B Preferred that may
be purchased for an amount equal to $127,500,000 reduced by the aggregate amount
of all previous Capital Calls funded in accordance with the terms of this
Agreement and the purchase of Initial Shares hereunder. Notwithstanding the
foregoing, no Investor may exercise an Investor Call Right at any time after the
Board of Directors, including a majority of the Investor Appointees, has
approved a Qualified Public Offering or Liquidation Event, as those terms are
defined in the Stockholders' Agreement.

                  Upon the receipt by the Company of a written request signed on
behalf of Investors holding at least 60% of the shares of Series B Preferred
then outstanding (an "Investor Call Request"), the Company shall provide to each
Investor a notice (the "Investor Call Notice") setting forth (i) the number of
shares of Series B Preferred that may be acquired by each Investor if such
Investor exercised its Investor Call Right and (ii) the Contribution Date with
respect to such Investor Call Right, which Contribution Date shall be no earlier
than the 21st business day following the date of the Investor Call Notice. To
exercise its Investor Call Right, an Investor must notify the Company in writing
within 10 business days after the date of an Investor Call Notice of the number
of shares of Series B Preferred (up to the number set forth in the Investor Call
Notice) that such Investor desires to purchase pursuant to the Investor Call
Right (each, an "Investor Call Exercise Notice").

                  On the Contribution Date with respect to the Investor Call
Right, (i) the Company shall deliver to the Investors who are acquiring shares
of Series B Preferred pursuant to the Investor Call Right an Officer's
Certificate substantially in the form as set forth in Exhibit I, (ii) each
Investor who exercises its Investor Call Right shall acquire the number of
shares of Series B Preferred specified in the Investor Call Exercise

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Notice and shall make payment therefor by wire transfer to a bank account
designated by the Company, and (iii) the Company shall immediately deliver to
such Investor a certificate representing the shares of Series B Preferred that
such Investor is purchasing pursuant to such Investor Call Right.

          SECTION 3.3 EARLY TERMINATION OF THE TAKEDOWN PERIOD.

                  (a) Subject to Section 3.3(b), the Takedown Period shall
terminate upon the earliest to occur of any of the following events:

                         (i) the consummation of (A) an initial public offering
     of the Company's common stock, par value $.001 per share (the "Common
     Stock"), in which (x) the aggregate gross proceeds to the Company are not
     less than $50,000,000, (y) each share of Series B Preferred would convert
     pursuant to paragraph 5 of the Series B Articles Supplementary at the
     Conversion Ratio (as defined in the Series B Preferred Articles
     Supplementary) into shares of Common Stock that have an aggregate value,
     based on the price to public in the initial public offering, of at least
     $7.50 per share, and (z) the Common Stock is authorized and approved for
     listing on the New York Stock Exchange or admitted to trading and quoted in
     the Nasdaq National Market system, or (B) any initial public offering of
     the Company's Common Stock which at least two of the Investor Appointees
     approve shall terminate the Takedown Period;

                         (ii) the affirmative vote of the Investors holding 60%
     or more of the outstanding shares of Series B Preferred to terminate the
     Takedown Period upon prior written notice to the Company and the other
     Investors;

                         (iii) the occurrence of an Insolvency Event (as defined
     below); or

                         (iv) the occurrence of a dissolution, liquidation or
     winding up, or sale of all or substantially all of the assets, or a Change
     of Control (as such term is defined in the Stockholders' Agreement) of the
     Company.

As used in Section 3.3(a)(iii), an "Insolvency Event" means (1) the Company or
any of its subsidiaries shall commence a voluntary case or other proceeding
seeking liquidation, reorganization with respect to itself or its debts under
any bankruptcy, insolvency or other similar law now or hereafter in effect or
seeking the appointment of a trustee, receiver, liquidator, custodian or other
similar official of it or any substantial part of its property, or shall consent
to any such relief or to the appointment of or taking possession by any such
official in an involuntary case or other proceeding commenced against it, or
shall make a general assignment for the benefit of creditors, or shall fail
generally to pay its debts as they become due, or shall take any corporate
action to authorize any of the

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foregoing; (2) an involuntary case or other proceeding shall be commenced
against the Company or any of its subsidiaries seeking liquidation,
reorganization or other relief with respect to it or its debts under bankruptcy,
insolvency or other similar law now or hereafter in effect or seeking the
appointment of a trustee, receiver, liquidator, custodian or other similar
official of it or any substantial part of its property, and such involuntary
case or other proceeding shall remain undismissed and unstayed for a period of
60 days; or (3) an order for relief shall be entered against the Company or any
of its subsidiaries under the federal bankruptcy laws now or hereafter in effect
or the Company admits in writing that it cannot pay its debts when due.

                  (b) Notwithstanding Section 3.3(a), the Takedown Period may
not be terminated pursuant to clause (ii) of Section 3.3(a) with respect to any
Capital Calls for which the Company has validly requested such Capital Call
pursuant to a Call Notice and such Capital Call is necessary for the Company to
perform its obligations with respect to any proposed acquisition cost or other
capital expenditure of the type described in Section 7.4(i) with respect to
which the Company has entered into a legally binding agreement prior to the date
of issuance of the notice referred to in Section 3.3(a)(ii); provided further,
however, that the Company may not issue any Call Notices after the issuance of a
termination notice pursuant to Section 3.3(a)(ii) above.

          SECTION 3.4 RIGHTS OF INVESTORS.

          Each Investor, in its sole and absolute discretion, may exercise or
refrain from exercising any rights or privileges that such Investor may have
pursuant to this Agreement, the Registration Rights Agreement, the Stockholders'
Agreement, the Restated Articles, the Series B Articles Supplementary, the
Bylaws or at law or in equity, and such Investor shall not incur or be subject
to any liability or obligation to the Company, any other Investor or holder of
shares of Series B Preferred, any other stockholder or security holder of the
Company or any other Person, by reason of exercising or refraining from
exercising any such rights or privileges.

          SECTION 3.5 NO COMMITMENT FOR ADDITIONAL FINANCING.

          The Company acknowledges and agrees that no Investor has made any
representation, undertaking, commitment or agreement to provide or assist the
Company in obtaining any financing, investment or other assistance, other than
the Total Commitment as set forth in this Agreement and subject to all
conditions set forth herein. In addition, the Company acknowledges and agrees
that (i) no statements, whether written or oral, made by any Investor or its
representatives on or after the date hereof shall create an obligation,
commitment or agreement to provide or assist the Company in obtaining any
financing or investment, (ii) the Company shall not rely on any such statement
by any Investor or its representatives, and (iii) an obligation, commitment or
agreement to provide or assist the Company in obtaining any financing or
investment may only be created by a written agreement, signed by such Investor
and the Company, setting forth the terms and conditions of such financing or
investment and stating that the parties intend for such writing to be a binding
obligation or agreement. Each Investor shall have the right, in its sole and
absolute discretion, to refuse or decline to participate

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in any other financing of or investment in the Company, and shall have no
obligation to assist or cooperate with the Company in obtaining any financing,
investment or other assistance.

          SECTION 3.6 EXCULPATION AMONG INVESTORS.

          Each Investor acknowledges that it is not relying upon any other
Investor, or any officer, director, stockholder, employee, agent, partner or
affiliate of any such other Investor, in making its investment or decision to
invest in the Company or in monitoring such investment. Each Investor agrees
that no other Investor nor any officer, director, stockholder, employee, agent,
partner or affiliate of any other Investor shall be liable for any action
heretofore or hereafter taken or omitted to be taken by any of them relating to
or in connection with the Company or the shares of Series B Preferred, or both.
Without limiting the foregoing, no Investor nor any of its officers, directors,
stockholders, partners, employees, agents or affiliates, or other holder of any
shares of Series B Preferred shall have any obligation, liability or
responsibility whatsoever for the accuracy, completeness or fairness of any or
all information about the Company or any subsidiary or their respective
properties, business or financial and other affairs, acquired by such Investor
or holder from the Company or any subsidiary or the respective officers,
directors, employees, agents, representatives, counsel or auditors of either,
and in turn provided to another Investor or holder of shares of Series B
Preferred, nor shall any such Investor or other Person have any obligation or
responsibility whatsoever to provide any such information to any other Investor
or holder of shares of Series B Preferred or to continue to provide any such
information if any information is provided. For purposes of this Section 3.6,
the Company shall be deemed to not be an affiliate of any Investor.

                                   ARTICLE IV

                       NON-PARTICIPATION; EVENT OF DEFAULT

          SECTION 4.1 NON-PARTICIPATION BY AN INVESTOR.

          Each of Warburg Pincus Private Equity VIII, L.P. ("Warburg"), and GS
Capital Partners 2000, L.P., GSCP 2000 Offshore BBOG Holding, L.P., GSCP 2000
GmbH BBOG Holding, L.P., GS Capital Partners 2000 Employee Fund, L.P., Stone
Street Fund 2000, L.P., Stone Street BBOG Holding and Goldman Sachs Direct
Investment Fund 2000, L.P. (collectively, the "Goldman Funds"), and J.P. Morgan
Partners (BHCA), L.P. ("J.P. Morgan") shall have the right to become a
"Non-Participating Investor" in the event that (i) the Company delivers a Call
Notice for a Capital Call the funding of which would result in the Company
having made Capital Calls during any fiscal year in an aggregate amount (the
"Capital Call Threshold") for that fiscal year of $25,000,000 in excess of the
total amount of Capital Calls provided for in the annual budget of the Company
for such fiscal year then in effect and approved in advance by the Board of
Directors of the Company, including a majority of the Investor Appointees in
accordance with the Stockholders' Agreement, and (ii) such Investor notifies the
Company in writing within five business days after the giving of such Call
Notice that it will not pay its share of such capital contributions. None of
Warburg, the

                                       9
<PAGE>

Goldman Funds, and J.P. Morgan shall have the right to become a
Non-Participating Investor in the event that the Call Notice requests capital
contributions that are in an amount below the Capital Call Threshold when
aggregated with all prior completed Capital Calls in such fiscal year, or for
any portion of such Capital Call that does not, when aggregated with all prior
completed Capital Calls in such fiscal year, exceed the Capital Call Threshold.
In the event that any of Warburg, the Goldman Funds or J.P. Morgan elect to
become a Non-Participating Investor, the Company shall provide written notice to
all Investors of such election (the "Non-Participation Notice"). Each Investor
other than Warburg, the Goldman Funds and J.P. Morgan shall have the right to
become a Non-Participating Investor by notifying the Company in writing within
five business days after the giving of the Non-Participation Notice. If the
Company cancels a Capital Call for which any Investor had elected to become a
Non-Participating Investor, such Investor shall not be deemed to be a
Non-Participating Investor with respect to such Capital Call unless such Capital
Call is cancelled because the Company is unable to raise enough funds to fund
the transaction which necessitated the Capital Call. The Remaining Commitment of
a Non-Participating Investor shall automatically become zero. Upon receipt of
notification that any Investors have elected to become a Non-Participating
Investor, the Company shall provide notice to each Investor who is not a
Non-Participating Investor or a Defaulting Investor and offer each such Investor
the opportunity to increase such Investor's Total Commitment by an amount up to
such Investor's ratable share of the portion of the Non-Participating Investor's
Total Commitment that will not be funded, as determined among all of the
eligible Investors electing to increase their Total Commitments. In the event
that an Investor elects to increase its Total Commitment, Annex A will be
appropriately adjusted to reflect such increase, and the Capital Call will be
allocated ratably among the revised Remaining Commitments of the participating
Investors.

          SECTION 4.2 DEFAULT BY AN INVESTOR.

                  (a) An "Event of Default" shall be deemed to have occurred if
(i) any Investor (any such Investor, a "Defaulting Investor") fails or refuses
to consummate the sale and purchase of Series B Preferred representing its
complete portion of any Capital Call validly made (other than as permitted by
Section 4.1), and (ii) such default has continued in whole or in part for not
less than five days after the Contribution Date.

                  (b) Upon an Event of Default, the Company may, at its option,
undertake any of the following: (A) terminate the Defaulting Investor's right to
participate in any future Capital Calls (in which event the Remaining Commitment
of such Investor shall automatically be reduced to zero), (B) implement the
repurchase provisions of Section 4.3 of the Stockholders' Agreement with respect
to the Series B Preferred eligible to be repurchased at the time of such Capital
Call, (C) institute suit against a Defaulting Investor for such Investor's
defaulted portion of the Capital Call precipitating such Event of Default (and
not for the amount of any Capital Calls, individually or in the aggregate, in
excess of the Capital Call Threshold), as well as (x) interest on past due
amounts at a rate equal to the lesser of the maximum amount permitted by
applicable law and the Prime Rate (as determined by U.S. Bank N.A. of

                                       10
<PAGE>

Denver, Colorado) plus five percent (5%) per annum and (y) reasonable costs and
expenses of the Company in connection with such Event of Default, and/or (D)
allow each Investor who is not a Defaulting Investor or Non-Participating
Investor to elect to increase its Total Commitment by such Investor's ratable
share of the amount of the unfunded Total Commitment of the Defaulting Investor.
In addition, the Company may pursue any other rights and remedies available to
the Company at law or equity. In the event that an Investor elects to increase
its Total Commitment, Annex A will be appropriately adjusted to reflect such
increase.

          SECTION 4.3 LOSS OF CERTAIN RIGHTS.

          A Defaulting Investor or a Non-Participating Investor (i) shall have
no right to participate in funding its portion of any future Capital Call, (ii)
shall cause its representative on the Board of Directors, if any, to resign,
(iii) shall have no right to place any representative on the Board of Directors
pursuant to the Stockholders' Agreement, (iv) will be subject to having its
representative on the Board of Directors be removed at the time it becomes a
Defaulting Investor or a Non-Participating Investor, if such representative does
not resign, and (v) will have no right to vote its shares of Series B Preferred
or Common Stock on matters or consent to actions pursuant to the Stockholders'
Agreement or this Agreement other than as specifically provided herein or
therein; provided, however, that the foregoing provision shall not be construed
as limiting or restricting the rights of a Defaulting Investor or a
Non-Participating Investor to vote its shares of capital stock on matters with
respect to which holders of capital stock have the right to vote under the
Articles of Incorporation or the Bylaws, pursuant to the Maryland General
Corporation Law, as amended (the "MGCL"), or the Registration Rights Agreement;
and provided further that the Company will use reasonable best efforts to permit
a Defaulting Investor or Non-Participating Investor to retain or obtain and
exercise such management rights in order for such investment to be a "venture
capital investment," as defined in the United States Department of Labor's "Plan
Assets" Regulation.

                                   ARTICLE V

                  REPRESENTATIONS AND WARRANTIES OF THE COMPANY

          The Company represents and warrants to, and agrees with each of the
Investors that:

          SECTION 5.1 ORGANIZATION; GOOD STANDING; QUALIFICATION.

          The Company is a corporation duly organized, validly existing and in
good standing under the laws of the State of Maryland and has all requisite
corporate power and corporate authority to carry on its business as now
conducted and as presently proposed to be conducted. The Company is duly
licensed or qualified to transact business as a foreign corporation and is in
good standing in each jurisdiction in which the nature of the business
transacted by it or the character of the properties owned or leased by it
requires such licensing or qualification, except for those jurisdictions where
the

                                       11
<PAGE>

failure to be so licensed, qualified or in good standing would not have a
material adverse effect on the business, prospects, condition, affairs,
properties or assets of the Company (a "Material Adverse Effect").

          SECTION 5.2 CAPITALIZATION AND VOTING RIGHTS.

                  (a) The authorized capital of the Company consists of (i)
150,000,000 shares of Common Stock, par value $.001 per share, of which
8,386,644 shares of Common Stock are issued and outstanding as of the date
hereof and (ii) 75,000,000 shares of preferred stock, par value $.001 per share
(the "Preferred Stock"), of which (i) 6,900,000 shares have been designated the
Series A Preferred Stock, of which [_________] are issued and outstanding as of
the date hereof, and (ii) 51,000,000 shares have been designated the Series B
Preferred, none of which is issued and outstanding prior to the Closing, but up
to all of which may be issued and sold pursuant to the terms of this Agreement.

                  (b) The outstanding shares of Series A Preferred and Common
Stock have been duly authorized and validly issued, are fully paid and
nonassessable, and were issued in accordance with the registration or
qualification provisions of the Securities Act and any relevant state securities
laws or pursuant to valid exemptions therefrom.

                  (c) The outstanding shares of Common Stock are owned by the
stockholders and in the numbers specified in Exhibit J hereto. The outstanding
options are owned by the option holders in the number (including exercise price
and vesting) specified in Exhibit J hereto. In addition, the Company has
reserved 6,500,000 shares of its Common Stock for purchase upon exercise of
options to be granted in the future under the Company's 2002 Stock Option Plan.

                  (d) The Shares, when issued in accordance with the terms of
this Agreement, will constitute one hundred percent (100%) of the issued and
outstanding Series B Preferred.

                  (e) Except as set forth in Section 5.2(e) of the disclosure
schedule being delivered by the Company to the Investors simultaneously with the
execution of this Agreement (the "Disclosure Schedule") and as contemplated by
this Agreement and the Stockholders' Agreement, there is not outstanding any
option, warrant, right (contingent or other, including conversion, exchange,
participation, right of first refusal, co-sale or preemptive rights) or
agreements for the purchase or acquisition from the Company of any shares of its
capital stock or any options, warrants or rights convertible into or
exchangeable for any thereof. Except as disclosed in Section 5.2(e) of the
Disclosure Schedule, and as contemplated by this Agreement and the Stockholders'
Agreement, there is no commitment by the Company to issue shares, subscriptions,
warrants, options, convertible or exchangeable securities or other such rights
or to distribute to holders of its equity securities any evidence of
indebtedness or asset. Except as disclosed in Section 5.2(e) of the Disclosure
Schedule, and as contemplated by this Agreement, the Stockholders' Agreement,
and as provided in the Stockholders'

                                       12
<PAGE>

Agreement, dated as of January 31, 2002, by and among the Company and certain
stockholders thereof (the "Founders Stockholders' Agreement"): (i) the Company
is not a party or subject to any agreement or understanding, and, to the
Company's knowledge, there is no agreement or understanding between or among any
holders of the Company's capital stock relating to the acquisition, disposition
or voting or giving of written consents with respect to any security or matter,
or by a director of the Company; (ii) the Company has no obligation (contingent
or otherwise) to purchase, redeem or otherwise acquire any shares of its capital
stock or other securities or any interest therein or to pay any dividend or make
any other distribution in respect thereof; (iii) there are no restrictions on
the transfer of the Company's capital stock other than those arising from
securities laws; and (iv) no person or entity is entitled to (x) any preemptive
or similar right with respect to the issuance of any capital stock or other
securities of the Company or (y) any rights with respect to the registration of
any capital stock or other securities of the Company under the Securities Act.

          SECTION 5.3 SUBSIDIARIES.

          The Company has no subsidiaries. The Company does not own or control,
directly or indirectly, any interest in any other corporation, partnership,
limited liability company, association, or other business entity. The Company is
not a participant in any joint venture, partnership, or similar arrangement.

          SECTION 5.4 AUTHORIZATION.

          The Company has all requisite corporate power and authority to execute
and deliver this Agreement and the agreements contemplated herein to which it is
a party, and to issue and sell the Series B Preferred and the Common Stock
issuable upon conversion thereof, and to carry out the provisions of this
Agreement and the other agreements contemplated herein to which it is a party.
All corporate action on the part of the Company, its officers, directors and
stockholders necessary for the authorization, execution and delivery of this
Agreement and the agreements contemplated herein, and the performance of all
obligations of the Company hereunder and thereunder at the Closing and the
authorization, issuance (or reservation for issuance), sale, and delivery of the
Series B Preferred in accordance with this Agreement and the Common Stock
issuable upon conversion thereof has been taken. This Agreement and the
agreements contemplated herein have been duly and validly executed and delivered
and constitute, assuming this Agreement and such agreements have been duly
authorized, executed and delivered by the Investors, valid and legally binding
obligations of the Company, enforceable in accordance with their respective
terms except (i) as limited by applicable bankruptcy, insolvency,
reorganization, moratorium, and other laws of general application affecting
enforcement of creditors' rights generally, and (ii) as limited by laws relating
to the availability of specific performance, injunctive relief, or other
equitable remedies. Except as set forth in the Stockholders' Agreement, the sale
of the Series B Preferred is not, and the subsequent conversion of the Series B
Preferred into Common Stock will not be, subject to any preemptive rights or
rights of first refusal.

                                       13
<PAGE>

          SECTION 5.5 VALID ISSUANCE OF SERIES B PREFERRED AND COMMON STOCK.

          The Series B Preferred that is being purchased by the Investors
hereunder, when issued, sold, and delivered in accordance with the terms of this
Agreement for the consideration expressed herein, will be duly and validly
issued, fully paid, and nonassessable, and will be free of all restrictions
imposed by or through the Company other than restrictions as set forth in this
Agreement or the Stockholders' Agreement and under applicable state and federal
securities laws. The Common Stock issuable upon conversion of the Series B
Preferred being purchased pursuant to this Agreement has been duly and validly
reserved for issuance and, upon issuance in accordance with the terms of the
Restated Articles, will be duly and validly issued, fully paid, and
nonassessable and will be free of all restrictions imposed by or through the
Company other than restrictions set forth in this Agreement or the Stockholders'
Agreement and under applicable state and federal securities laws.

          SECTION 5.6 OFFERING.

          Based in part on the accuracy of the Investors' representations and
warranties set forth in this Agreement, the offer, sale and issuance of the
Shares as contemplated by this Agreement are exempt from the registration
requirements of the Securities Act, and will be issued in compliance with all
applicable federal and state securities laws. Neither the Company nor anyone
acting on its behalf will take any action hereafter that would cause the loss of
such exemption. Neither the Company nor any person acting on its behalf has
engaged, in connection with the offering of the Series B Preferred, in any form
of general solicitation or general advertising within the meaning of Rule 502(c)
under the Securities Act. The issuance of the Series B Preferred to the
Investors will not be integrated with any other issuance of the Company's
securities (past, current or future) for purposes of any stockholder approval
provisions applicable to the Company or its securities.

          SECTION 5.7 CONSENTS.

          No consent, approval, order or authorization of, or registration,
qualification, designation, declaration or filing with, any federal, state or
local governmental authority or any person or entity is required on the part of
the Company in connection with the execution, delivery and performance by the
Company of this Agreement and issuance, sale and delivery of the Shares, or the
issuance of Common Stock upon conversion of the Series B Preferred, except (i)
the filing of the Restated Articles with the Secretary of State of the State of
Maryland, and (ii) such filings as have been made prior to the Closing, except
any notices of sale required to be filed with the Securities and Exchange
Commission under Regulation D of the Securities Act, or such post-closing
filings as may be required under applicable state securities laws, which will be
timely filed within the applicable periods therefor.

                                       14
<PAGE>

          SECTION 5.8 COMPLIANCE WITH OTHER INSTRUMENTS.

          The Company is not in violation or default of (i) any provision of its
Articles of Incorporation or Bylaws, (ii) any provision of any mortgage,
indenture, contract, lease, agreement or instrument to which it is a party or by
which it is bound, or (iii) any judgment, decree, order, writ, federal or state,
statute, rule or regulation, license or permit of any governmental authority
applicable to it, which, in the case of clauses (ii) and (iii), could reasonably
be expected, individually or in the aggregate, to have a Material Adverse Effect
on the Company. The execution, delivery and performance by the Company of this
Agreement and the agreements and transactions contemplated hereby will not (a)
conflict with or result in, with or without the passage of time or giving of
notice or both, either in any default or loss of rights under, acceleration of,
or give rise to any right of termination, acceleration or modification, under
any such provision, mortgage, indenture, contract, lease, agreement, instrument,
judgment, decree, order or writ or (b) result in the creation of any mortgages,
pledges, security interests, liens, charges, claims, restrictions, easements or
other encumbrances of any nature ("Liens") upon any of the properties or assets
of the Company. The Company does not have any knowledge of any termination or
material breach or anticipated termination or material breach by the other party
to any material contract or commitment to which it is a party or to which any of
its assets is subject. The Company's execution and delivery of this Agreement
and its performance of the transactions and agreements contemplated hereby will
not violate any instrument, agreement, judgment, decree, order, statute, rule or
regulation of any governmental authority applicable to the Company.

          SECTION 5.9 COMPLIANCE WITH LAWS.

          The Company has all franchises, permits, licenses and other rights and
privileges from governmental authorities necessary to permit it to own its
property and to conduct its business as it is presently conducted and as
contemplated to be conducted, except where the failure to have any such
franchises, permits, licenses or other rights or privileges would not reasonably
be expected to, individually or in the aggregate, have a Material Adverse Effect
of the Company. The Company is not in violation of any law, regulation,
authorization or order of any public authority relevant to the ownership of its
properties or the carrying on of its business as it is presently conducted and
as contemplated to be conducted, except for any such violations which would not
reasonably be expected to, individually or in the aggregate, have a Material
Adverse Effect of the Company, and to the Company's knowledge, no material
expenditures are or will be required in order to comply with any such existing
law, regulation, authorization or order.

          SECTION 5.10 ENVIRONMENTAL MATTERS.

          Except as set forth on Schedule 5.10, (i) the Company has complied
with and is in compliance with all federal, state, local and foreign statutes
(civil and criminal), laws, ordinances, regulations, rules, notices, permits,
judgments, orders and decrees applicable to it or any of its properties, assets,
operations and businesses relating to environmental protection (collectively
"Environmental Laws") including, without

                                       15
<PAGE>

limitation, Environmental Laws relating to air, water, land and the generation,
storage, use, handling, transportation, treatment or disposal of Hazardous
Wastes, Hazardous Materials and Hazardous Substances (as such terms are defined
in any applicable Environmental Law) including petroleum and petroleum products;
(ii) the Company has obtained and adhered to all permits and other approvals
necessary to treat, transport, store, dispose of and otherwise handled Hazardous
Wastes, Hazardous Materials and Hazardous Substances, and has reported to the
appropriate authorities, to the extent required by all Environmental Laws, all
past and present sites owned and operated by the Company where Hazardous Wastes,
Hazardous Materials or Hazardous Substances have been treated, stored, disposed
of or otherwise handled; (iii) there have been no releases or threats of
releases (as defined in Environmental Laws) at, from, in or on any property
owned or operated by the Company except as permitted by Environmental Laws; (iv)
to the best of the Company's knowledge, no on-site or off-site location to which
the Company has transported or disposed of Hazardous Wastes, Hazardous Materials
and Hazardous Substances or arranged for the transportation of Hazardous Wastes,
Hazardous Materials and Hazardous Substances is the subject of any federal,
state, local or foreign enforcement action or any other investigation which
could lead to any material claim against the Company for any clean-up cost,
remedial work, damage to natural resources, property damage or personal injury,
including, but not limited to, any claim under the Comprehensive Environmental
Response, Compensation and Liability Act of 1980, the Resource Conservation and
Recovery Act, the Hazardous Materials Transportation Act or comparable state or
local statutes and regulations, each as amended; and (v) the Company has no
contingent liability in connection with any release of any Hazardous Waste,
Hazardous Materials or Hazardous Substance into the environment.

          SECTION 5.11 RELATED PARTY TRANSACTIONS.

          Except as disclosed in Section 5.11 of the Disclosure Schedule, no
employee, officer, stockholder or director of the Company or member of his or
her immediate family is indebted to the Company, nor is the Company indebted (or
committed to make loans or extend or guarantee credit) to any of them, other
than (i) for payment of salary for services rendered by officers, directors or
employees, (ii) reimbursement for reasonable expenses incurred by officers,
directors or employees on behalf of the Company, and (iii) for other standard
employee benefits made generally available to all employees (including stock
option agreements outstanding under the Company's 2002 Stock Option Plan). To
the Company's knowledge, none of such persons has any ownership interest,
directly or indirectly, in any firm or corporation with which the Company is
affiliated or with which the Company has a business relationship, or any firm or
corporation that competes with the Company, except that employees, stockholders,
officers, or directors of the Company and members of their immediate families
may have an immaterial beneficial ownership interest in publicly traded
companies that may compete with the Company. To the Company's knowledge, no
officer, director, or stockholder or any member of their immediate families is a
party to or is, directly or indirectly, interested in any agreement,
understanding or proposed transaction with the Company (other than such written
agreements as relate to any such person's ownership of capital stock or other
securities of the Company).

                                       16
<PAGE>

          SECTION 5.12 REGISTRATION RIGHTS.

          Except as provided in the Registration Rights Agreement, the Company
has not granted or agreed to grant any registration rights relative to the
registration of its securities under the Securities Act, including piggyback
registration rights, to any person or entity.

          SECTION 5.13 TITLE TO PROPERTY AND ASSETS.

          The Company has good, valid and marketable title to its properties and
assets, and all such properties and assets are free and clear of all Liens other
than Liens which do not, individually or in the aggregate, materially impair the
continued use and operation of the assets to which they relate in the business
of the Company as presently conducted. With respect to the property and assets
it leases, the Company is in compliance with such leases and holds a valid
leasehold interest free of any liens, claims, or encumbrances, except such liens
and encumbrances which are not material in nature or amount and do not
materially impair the Company's use of such leased property. All leases of real
or personal property to which the Company is a party are fully effective and
afford the Company peaceful and undisturbed possession of the property which is
the subject matter of the lease.

          SECTION 5.14 EMPLOYEES; EMPLOYEE COMPENSATION.

          The Company is not delinquent in payments to any of its employees for
any wages, salaries, commissions, bonuses or other direct compensation for any
services performed for it as of the date hereof or amounts required to be
reimbursed to such employees. The Company is not bound by or subject to (and
none of its assets or properties are bound by or subject to) any written or
oral, express or implied, contract, commitment or arrangement with any labor
union, and no labor union has requested or, to the knowledge of the Company, has
sought to represent any of the employees of the Company. There is no strike or
other labor dispute involving the Company pending or, to the knowledge of the
Company, threatened, which could have a material adverse effect on the assets,
properties, financial condition, operating results, or business of the Company
(as such business is presently conducted and as it is proposed to be conducted),
nor is the Company aware of any labor organization activity involving its
employees. With respect to each employee plan presently in force within the
meaning of the Employee Retirement Income Security Act of 1974, as amended
("ERISA") that is sponsored or maintained by the Company, such plan has been
administered in compliance in all material respects with its terms and the
applicable requirements of ERISA and the Internal Revenue Code of 1986, as
amended. The Company has not contributed to and is not required to contribute to
any multiemployer plan within the meaning of section 3(37) of ERISA. The Company
has complied in all material respects with all applicable state and federal
equal opportunity and other laws related to employment. The Company is not a
party to or bound by any currently effective employment contract, deferred
compensation agreement, bonus plan, incentive plan, profit sharing plan,
retirement agreement, or other employee compensation agreement other than the
Company's 2002 Stock Option Plan and any award agreements entered into

                                       17
<PAGE>

thereunder and other than the issuance of 8,386,644 restricted shares of Common
Stock to certain management employees. No officer or key employee, or any group
of key employees, intends to terminate their employment with the Company, nor
does the Company have a present intention to terminate the employment of any of
the foregoing. For purposes of the previous sentence, officers and key employees
shall consist of William J. Barrett, John F. Keller, Robert W. Howard, Fredrick
J. Barrett, Terry R. Barrett, Kurt M. Reinecke, and Dominic Bazile. Subject to
general principles related to wrongful termination of employees, the employment
of each officer and employee of the Company is terminable at the will of the
Company.

          SECTION 5.15 TAX MATTERS.

          The Company: (i) has timely filed all federal, state, local and other
tax returns (collectively, the "Tax Returns") that are required to have been
filed by it with all appropriate governmental agencies and all such Tax Returns
are true, complete and correct in all material respects and fairly reflect
operations for tax purposes; (ii) has timely paid all taxes, charges, fees,
levies or other assessments shown to be due on such Tax Returns or imposed by
any taxing authority (collectively, "Taxes") (other than taxes or assessments
the validity of which are being contested in good faith by appropriate
proceedings); (iii) has complied in all material respects with all applicable
laws relating to the payment and withholding of Taxes and has timely withheld
and paid over to the proper taxing authorities all amounts required to be
withheld and paid under all applicable laws; (iv) has not waived any statute of
limitations with respect to Taxes or agreed to any extension of time within
which to file any Tax Return for any taxable period, which such Tax Return has
not since been filed or to extend the period for the assessment or collection of
any Taxes; and (v) has provided adequate accruals for the payment of all Taxes
not yet due and payable (including deferred income taxes). To the Company's
knowledge, there are no pending or threatened audits, examinations,
investigations, or other proceedings in respect of Taxes or Tax Returns of the
Company. There are no encumbrances for Taxes upon the assets or properties of
the Company except for statutory liens for Taxes not yet due.

          SECTION 5.16 MINUTE BOOKS.

          The minute books of the Company contain a complete and accurate record
of all meetings and all actions by written consent of the stockholders, the
Board of Directors, or any committees thereof since the date of incorporation of
the Company. The stock ledger of the Company provided to Vinson & Elkins L.L.P.
is complete and reflects all issuances, repurchases, cancellations and, to the
knowledge of the Company, transfers of shares of capital stock of the Company.

          SECTION 5.17 INVESTMENT COMPANY ACT.

          The Company is not an "investment company" as that term is defined in,
and is not otherwise subject to regulation under, the Investment Company Act of
1940.

                                       18
<PAGE>

          SECTION 5.18 NO PRIOR ACTIVITIES.

          The Company was incorporated on January 7, 2002 and since such date
the Company has not, directly or indirectly, (a) engaged in any business, (b)
entered into any agreements, contracts or other commitments or (c) incurred any
liabilities of any nature (matured or unmatured, fixed or contingent), except:

                         (i) the Company has issued 8,386,644 shares of Common
     Stock (after giving effect to the stock split as of March 25, 2002) and
     issued or committed to issue on or before the date that is 14 days from the
     date hereof 6,594,724 shares of Series A Preferred (as described in Section
     1.4 above), and entered into related agreements, as described more fully in
     Section 5.18 of the Disclosure Schedule;

                         (ii) the Company has negotiated, executed and delivered
     this Agreement and the agreements contemplated hereby or annexed hereto;

                         (iii) the Company has negotiated, executed and
     delivered Engagement Agreements relating to the prior offerings of Common
     Stock and the offering of the Series B Preferred contemplated hereby with
     Petrie Parkman & Co. and First Albany Corporation;

                         (iv) the Company has incurred general and
     administrative expenses and entered into agreements with respect to
     obtaining office space, office equipment, its employees and outside
     attorneys and agents;

                         (v) the Company has pursued its strategy of seeking
     acquisitions of oil and gas properties, and in connection therewith, has
     reviewed potential acquisitions, executed confidentiality agreements,
     retained consultants and entered into related obligations and incurred
     related expenses, including an agreement to purchase certain oil and gas
     properties in the Wind River Basin for a purchase price of approximately
     $73 million in cash and a Letter of Intent, dated as of March 11, 2002, by
     and between the Company and the Crow Tribe with respect to the evaluation,
     the purchase of an option, and the potential leasing of certain land;

                         (vi) the Company has incurred debt in an amount not in
     excess of $2,720,000 including pursuant to a convertible promissory note
     with Hennie L.J.M. Gieskes to be executed within 14 days from the date
     hereof in the principal amount of $1.9 million that is convertible into
     455,635 shares of Series A Preferred, which promissory note shall be
     approved by a majority of the Investor Appointees; and

                         (vii) the Company is currently negotiating a purchase
     and sale agreement to acquire properties in the Uinta Basin.

                                       19
<PAGE>

All of the contracts and commitments identified above are in full force and
effect and neither the Company, nor, to the knowledge of the Company, any other
party is in default thereunder (nor, to the knowledge of the Company, has any
event occurred which with notice, lapse of time or both would constitute a
default thereunder), and the Company has not received notice of any alleged
default under any such contract or commitment. The Company does not have any
knowledge of any termination or material breach or anticipated termination or
material breach by the other party to any material contract or commitment to
which it is a party or to which any of its assets is subject.

          SECTION 5.19 LITIGATION.

          There is no action, suit, proceeding or investigation pending or, to
the knowledge of the Company, threatened against the Company, or against any
officer or director nor, to the knowledge of the Company, has there occurred any
event nor does there exist any condition on the basis of which any material
litigation, proceeding or investigation might properly be instituted. The
Company is not a party or subject to any order, writ, injunction, judgment or
decree of any court or government agency or instrumentality.

          SECTION 5.20 CERTAIN AGREEMENTS OF OFFICERS AND EMPLOYEES.

          To the Company's knowledge, no officer, employee or consultant of the
Company is, or is expected to be, in violation of any term of any employment
contract, patent disclosure agreement, proprietary information agreement,
noncompetition agreement, nonsolicitation agreement, confidentiality agreement
or any other similar contract or agreement or any restrictive covenant in
existence as of the date hereof, relating to the right of any such officer,
employee, or consultant to be employed or engaged by the Company because of the
nature of the business conducted or to be conducted by the Company or relating
to the use of trade secrets or proprietary information of others, and to the
Company's knowledge, the continued employment or engagement of the Company's
officers, employees or consultants does not subject the Company to any liability
with respect to any of the foregoing matters.

          SECTION 5.21 BROKERS.
Except for the fees and expenses that will be due to Petrie Parkman & Co. and
First Albany Corporation, which will be paid by the Company, no person, firm or
corporation has or, as a result of any action taken by the Company or any of its
authorized representatives, will have, in the context of the transactions
contemplated by this Agreement, any rights, interest or valid claim against or
upon the Company or the Investors for any commission, fee or other compensation
as a finder or broker or in any similar capacity.

          SECTION 5.22 FINANCIAL STATEMENTS.

                  (a) The Company has delivered to each Investor who has
requested such information its unaudited financial statements (including,
balance sheet and profit and loss statement, statement of stockholders' equity
and statement of cash

                                       20
<PAGE>

flows) as of February 28, 2002, for the period from inception on January 7, 2002
and ended on February 28, 2002 (the "Financial Statements"). Except as set forth
in Schedule 5.22(a) of the Disclosure Schedule, the Financial Statements have
been prepared in accordance with generally accepted accounting principles
("GAAP") applied on a consistent basis throughout the periods indicated, subject
to normal year-end adjustments and except that the unaudited Financial
Statements do not contain footnotes. The Financial Statements fairly present the
financial condition and operating results of the Company as of the dates, and
for the periods, indicated therein.

                  (b) Except as set forth in the Financial Statements, the
Company does not have and is not subject to any material liabilities or
obligations, contingent or otherwise, other than (i) liabilities incurred in the
ordinary course of business and (ii) obligations under contracts and commitments
incurred in the ordinary course of business and not required under GAAP to be
reflected in the Financial Statements, which, in both cases, individually or in
the aggregate, are not material to the financial condition or operating results
of the Company and do not exceed $25,000.

                  (c) Except as disclosed in the Financial Statements, the
Company is not a guarantor or indemnitor of any indebtedness of any other
person, firm, or corporation.

                  (d) The Company maintains and will continue to maintain a
standard system of accounting established and administered in accordance with
GAAP.

          SECTION 5.23 DISCLOSURE.

          The information concerning the Company provided by the Company to the
Investors prior to the date hereof does not contain any untrue statement of a
material fact or omit to state a material fact necessary to make the statement
contained therein, in light of the circumstances under which they are made, not
misleading.

                                   ARTICLE VI

                 REPRESENTATIONS AND WARRANTIES OF THE INVESTORS

     Each Investor hereby represents and warrants (as to itself only), severally
but not jointly, to the Company that:

          SECTION 6.1 AUTHORIZATION.

          Such Investor has full power and authority to execute and deliver this
Agreement and the other agreements contemplated herein to which it is a party,
and to carry out the provisions of this Agreement and the other agreements
contemplated herein to which it

                                       21
<PAGE>

is a party. All corporate or partnership action on the part of the Investor
necessary for the authorization, execution and delivery of this Agreement and
the performance of all obligations of the Investor hereunder at the Closing has
been taken. All corporate or partnership action on the part of the Investor
necessary for the authorization, execution and delivery of the agreements
contemplated herein to which it is a party will be taken prior to the Closing.
This Agreement has been duly and validly executed and delivered and constitutes,
and the agreements contemplated herein to which the Investor is a party when
executed and delivered will constitute, assuming due execution and delivery by
the Company of this Agreement and the agreements contemplated herein, valid and
legally binding obligations of such Investor, enforceable against such Investor
in accordance with their respective terms, except (i) as limited by applicable
bankruptcy, insolvency, reorganization, moratorium, and other laws of general
application affecting enforcement of creditors' rights generally, and (ii) as
limited by laws relating to the availability of specific performance, injunctive
relief, or other equitable remedies.

          SECTION 6.2 PURCHASE ENTIRELY FOR OWN ACCOUNT.

          This Agreement is made with each Investor in reliance upon such
Investor's representation to the Company, which by such Investor's execution of
this Agreement such Investor hereby confirms, that the shares of Series B
Preferred to be purchased by such Investor and the Common Stock issuable upon
conversion thereof (collectively, the "Securities") will be acquired for
investment for such Investor's own account, not as a nominee or agent, and not
with a view to the resale or distribution of any part thereof, and that such
Investor has no present intention of selling, granting any participation in, or
otherwise distributing the same, subject, in the case of J.P. Morgan, to the
qualifications set forth in the Regulatory Side Letter. By executing this
Agreement, each Investor further represents that such Investor does not have any
contract, undertaking, agreement or arrangement with any person to sell,
transfer or grant participations to such person or to any third person, with
respect to any of the Securities, subject, in the case of J.P. Morgan, to the
qualifications set forth in the Regulatory Side Letter.

          SECTION 6.3 RELIANCE UPON INVESTORS' REPRESENTATIONS.

          Each Investor understands that the Series B Preferred is not, and any
Common Stock acquired on conversion thereof at the time of issuance may not be,
registered under the Securities Act on the ground that the sale provided for in
this Agreement and the issuance of securities hereunder is exempt from
registration under the Securities Act pursuant to Section 4(2) thereof.

          SECTION 6.4 RECEIPT OF INFORMATION.

          Each Investor believes it has received all the information such
Investor considers necessary or appropriate for deciding whether to purchase the
Shares. Each Investor further represents that such Investor has had an
opportunity to ask questions and receive answers from the Company regarding the
terms and conditions of the offering of the Series B Preferred and the business,
properties, prospects, and financial condition of the Company and to obtain
additional information (to the extent the Company possessed such information or
could acquire it without unreasonable effort or expense) necessary to verify the
accuracy of any information furnished to such Investor or to which such Investor
had access. The foregoing, however, does not limit or modify the

                                       22
<PAGE>

representations and warranties of the Company in Article V of this Agreement or
the right of the Investors to rely thereon.

          SECTION 6.5 INVESTMENT EXPERIENCE.

          Such Investor confirms that it has such knowledge and experience in
financial and business matters that such Investor is capable of evaluating the
merits and risks of an investment in the Series B Preferred and of making an
informed investment decision and understands that (i) this investment is
suitable only for an investor which is able to bear the economic consequences of
losing its entire investment, (ii) the purchase of the Series B Preferred to be
purchased by such Investor hereunder is a speculative investment which involves
a high degree of risk of loss of the entire investment, and (iii) there are
substantial restrictions on the transferability of, and there will be no public
market for, the Series B Preferred or the Common Stock into which it is
convertible, and accordingly, it may not be possible for such Investor to
liquidate such Investor's investment in case of emergency.

          SECTION 6.6 ACCREDITED INVESTOR.

          Such Investor is either: (i) an "Accredited Investor," as such term is
defined in Regulation D under the Securities Act; or (ii) not an Accredited
Investor and neither such Investor nor any beneficiary of any trust or any
investment client for whose account such Investor is purchasing is a citizen or
resident of the United States or any state, territory or possession thereof,
including but not limited to any estate of any such person, or any corporation,
partnership, trust or other entity created or existing under the laws thereof,
or any entity controlled or owned by any of the foregoing.

          SECTION 6.7 RESTRICTED SECURITIES.

          Each Investor understands that the Series B Preferred (and any Common
Stock issued on conversion thereof) may not be sold, transferred, or otherwise
disposed of without registration under the Securities Act or an exemption
therefrom, and that in the absence of either an effective registration statement
covering the Shares (or the Common Stock issued on conversion thereof) or an
available exemption from registration under the Securities Act, the Series B
Preferred (and any Common Stock issued on conversion thereof) must be held
indefinitely. In particular, each Investor is aware that the Series B Preferred
Stock (and any Common Stock issued on conversion thereof) may not be sold
pursuant to Rule 144 promulgated under the Securities Act unless all of the
conditions of that Rule are met. Among the conditions for use of Rule 144 may be
the availability of current information to the public about the Company. Such
information is not now available and the Company has no present plans to make
such information available.

          SECTION 6.8 LITIGATION.

          There is no action, suit, proceeding or investigation pending or, to
the knowledge of the Investor, threatened against the Investor which is
reasonably likely to call into question the validity of this Agreement or the
agreements contemplated hereby or any action taken or to be taken pursuant
hereto or thereto, nor, to the knowledge of the

                                       23
<PAGE>

Investor, has there occurred any event nor does there exist any condition on the
basis of which any such litigation, proceeding or investigation might properly
be instituted.

          SECTION 6.9 BROKERS OR FINDERS.

          Except for the fees and expenses that will be due to Petrie Parkman &
Co. and First Albany Corporation, which shall be paid by the Company, no person
has or will have, as a result of the issuance of the Series B Preferred pursuant
to this Agreement, any right, interest or valid claim against or upon the
Company for any commission, fee or other compensation as a finder or broker
because of any act or omission by such Investor or his or its respective agents.

          SECTION 6.10 JURISDICTION OF ORGANIZATION.

          Such Investor is organized and has its principal place of business in
the states set forth under its name on Annex A hereto.

                                  ARTICLE VII

                              ADDITIONAL AGREEMENTS

          SECTION 7.1 CONFIDENTIALITY.

          Each Investor agrees that all Confidential Information (as defined
below) shall be kept confidential by such Investor and shall not be disclosed by
such Investor in any manner whatsoever; provided, however, that (i) any of such
Confidential Information may be disclosed to directors, officers, employees and
authorized representatives (including without limitation attorneys, accountants,
consultants, bankers and financial advisors) of such Investor (collectively, for
purposes of this Section, "Investor Representatives"), each of which Investor
Representatives shall be bound by the provisions of this Section 7.1, (ii) any
disclosure of Confidential Information may be made to the extent to which the
Company consents in writing, (iii) any disclosure may be made of the terms of an
Investor's investment pursuant to this Agreement and the performance of that
investment to the extent in compliance with applicable law (whether in the
Investor's fundraising materials, on the website of the Investor or an
affiliate, to a regulator or otherwise); (iv) any disclosure may be made of
Confidential Information to an Investor's partners, prospective partners or
affiliates or their authorized representatives, each of whom shall be bound by
the provisions of this Section 7.1 as if an "Investor", and (v) Confidential
Information may be disclosed by any Investor or any Investor Representative to
the extent that the Investor or Investor Representative has received an opinion
from its counsel, in writing, that it is legally compelled to do so, provided
that, prior to making such disclosure, the Investor or Investor Representative,
as the case may be, advises the Company as soon as the Investor or Investor
Representative is requested to disclose the Confidential Information, consults
with the Company regarding such disclosure and, if requested by the Company,
assists the Company, at the Company's expense, in seeking a protective order to
prevent the requested disclosure, and provided further that the Investor or
Investor Representative, as the case may be,

                                       24
<PAGE>

discloses only that portion of the Confidential Information as is, in the
written opinion of its counsel, legally required. The term "Confidential
Information", as used herein, means all confidential and proprietary information
(irrespective of the form of communication) obtained by or on behalf of Investor
from the Company or its representatives, other than information which (i) was or
becomes generally available to the public other than as a result of a breach of
this Agreement by such Investor or any Investor Representative, (ii) was or
becomes available to such Investor on a nonconfidential basis prior to
disclosure to the Investor by the Company or its representatives or (iii) was or
becomes available to the Investor from a source other than the Company and its
representatives, provided that such source is not known by such Investor to be
bound by a confidentiality agreement with the Company.

          SECTION 7.2 PUBLIC ANNOUNCEMENTS.

          The Company may issue press releases and public announcements,
provided that, except as may be required by applicable law, the Company shall
not issue any press release that identifies any Investor or otherwise make any
public statement with respect to any Investor without the prior written consent
of such Investor (which consent shall not be unreasonably withheld). No Investor
shall, except as required by applicable law, issue any press release that
describes the transactions contemplated herein or identifies the Company or any
other Investor without the prior consent of the Company and the identified
party. Except to the extent disclosure thereof is permitted by clause (iii) of
Section 7.2, any such press release or public statement required by applicable
law shall only be made after reasonable notice to the other parties hereto.

          SECTION 7.3 FEES AND EXPENSES.

          Except as otherwise expressly provided in this Agreement, all fees and
expenses, including fees and expenses incurred in connection with this Agreement
and the transactions contemplated herein, shall be paid by the party incurring
such fee or expense; provided, however, that if the Closing is effected, the
Company shall pay (i) the legal fees and expenses of Vinson & Elkins L.L.P.,
counsel to the Investors who initially designate the Investor Appointees in
accordance with the terms of the Stockholders' Agreement, not to exceed $175,000
(the "Fee Cap") and shall, upon receipt of a bill therefor, reimburse the
reasonable out-of-pocket expenses of such counsel up to the Fee Cap and (ii)
shall pay the reasonable out-of-pocket expenses incurred by the Investors,
provided, however, that aggregate expenses in excess of $100,000 shall require
advance authorization from the Company's Chief Financial Officer.

          SECTION 7.4 USE OF PROCEEDS.

          The Company will use the proceeds from the sale of the Shares and each
Capital Call for: (i) acquisition costs and other capital expenditures
associated with the Company's business of acquiring (directly or indirectly) oil
and gas producing and nonproducing properties and leasehold interests primarily
in the Rocky Mountain region of the United States and costs associated with the
exploration or development thereof (or acquiring business entities whose primary
business and assets are to own, operate explore

                                       25
<PAGE>

or develop such assets), (ii) working capital needs, including the establishment
or replenishment of a working capital reserve, (iii) general and administrative
expenses (including costs of organizing the Company), and (iv) general corporate
purposes. The Company and the Investors acknowledge that it is their intention
that the Company become a fully integrated operating company with all of its
assets, rights, benefits, goodwill and ancillary business and other components
of its affairs being owned, directly or indirectly through any subsidiaries, by
the Company.

          SECTION 7.5 REINCORPORATION IN DELAWARE.

          Within 30 days after the date of this Agreement, the Company shall
consummate a merger with and into a Delaware corporation for the purpose of
reincorporating as a Delaware corporation, pursuant to which each share of
outstanding capital stock of the Company shall be converted into one share of
the same class and series as such share prior to the merger, with rights and
preferences identical in all respects to the rights and preferences of such
share prior to the merger. No shares of stock of the surviving corporation shall
remain issued or outstanding immediately following such merger, except for
shares of stock issued upon conversion of the outstanding capital stock of the
Company immediately prior to the merger.

          SECTION 7.6 AMENDED AND RESTATED 2002 STOCK OPTION PLAN.

          Within 14 days after the Closing, the Board of Directors of the
Company, including a majority of the Investor Appointees, will approve and adopt
an amended and restated 2002 Stock Option Plan (the "Revised Plan") and a form
stock option grant agreement (the "Grant Agreement"), which Revised Plan and
Grant Agreement will be approved and adopted in accordance with the terms of the
Stockholders' Agreement and which Grant Agreement will be used by the Company to
grant all options under the Revised Plan so long as the Stockholders' Agreement
is in effect.

                                  ARTICLE VIII

                  SURVIVAL OF REPRESENTATIONS; INDEMNIFICATION

          SECTION 8.1 SURVIVAL OF REPRESENTATIONS.

          The representations and warranties made by the Company contained in
Article V of this Agreement and the representations and warranties made by the
Investors contained in Article VI of this Agreement shall survive the Initial
Closing for a period of one year; provided, that the representations and
warranties set forth in Sections 5.1, 5.2, 5.4 and 5.14 shall survive
indefinitely; and provided, further, that any representations and warranties
given or deemed to be given in or pursuant to any Call Notice shall survive for
a period of one year from the date of the related capital contribution. The
covenants and agreements of the parties hereto contained in this Agreement or in
any of the Ancillary Agreements shall survive until performed in accordance with
their terms.

                                       26
<PAGE>

          SECTION 8.2 AGREEMENT TO INDEMNIFY.

          (a) Subject to the terms and conditions of this Article VIII, the
Company hereby agrees to indemnify, defend and hold harmless each of the
Investors and its successors and assigns, representatives and affiliates
(collectively, the "Investor Group") from and against all claims, actions or
causes of action, assessments, demands, losses, damages, judgments, settlements,
liabilities, costs and expenses, including, without limitation, interest,
penalties and reasonable attorneys' and accounting fees and expenses of any
nature whatsoever, whether actual or consequential (collectively, "Damages"),
asserted against, imposed upon or incurred directly by any member of the
Investor Group by reason of or resulting from a breach of any agreement or
representation or warranty or covenant by the Company contained herein or any of
the Ancillary Agreements.

          (b) Subject to the terms and conditions of this Article VIII, each of
the Investors (severally and not jointly) hereby agrees to indemnify, defend and
hold harmless the Company and its subsidiaries, and each officer and director of
the Company or of any of its subsidiaries and each affiliate thereof
(collectively, the "Company Group"), and their successors and assigns, from and
against all Damages, asserted against, imposed upon or incurred directly by any
member of the Company Group by reason of or resulting from a breach of any
agreement or representation, warranty or covenant by such Investor contained
herein or any of the Ancillary Agreements.

          SECTION 8.3 LIMITATION OF LIABILITY.

          The obligations and liabilities of each Investor with respect to
claims under Section 8.2 hereof ("Company Claims") to the Company Group and the
Company with respect to claims under Section 8.2 hereof ("Investor Claims") to
the Investor Group shall be subject to the following limitations:

          (a) No indemnification shall be required to be made by any Investor
under this Article VIII with respect to any Company Claim which results from the
breach of any representation, except to the extent that the aggregate amount of
Damages with respect to all of such claims incurred by the Company Group exceeds
$25,000, in which case, such Investor shall be liable only for Damages in excess
of such amount. No indemnification shall be required to be made by the Company
under this Article VIII with respect to any Investor Claim which results from
the breach of any representation, except to the extent that the aggregate amount
of Damages with respect to all of such claims incurred by the Investor Group
exceeds $25,000, in which case, the Company shall be liable only for Damages in
excess of such amount.

          (b) The amount of Damages any party is required to pay to indemnify
any other party pursuant to Section 8.2 as a result of any Company Claim or
Investor Claim shall be reduced to the extent of any amounts actually received
by the party seeking indemnification after the Initial Closing pursuant to the
terms of insurance policies (if any) covering such claim.

                                       27
<PAGE>

          SECTION 8.4 CONDITIONS OF INDEMNIFICATION.

          The obligations and liabilities of the Company to indemnify the
Investor Group and the Investors to indemnify the Company Group under Section
8.2 hereof with respect to Company Claims and Investor Claims, respectively,
resulting from the assertion of liability by third parties shall be subject to
the following terms and conditions:

          (a) The indemnified party will give the indemnifying party prompt
notice of any such claim, and the indemnifying party will undertake the defense
thereof by representatives of its own choosing reasonably satisfactory to the
indemnified party, provided that failure to provide such notice will not relieve
the indemnifying party of its obligations hereunder unless it is actually
prejudiced by such failure to receive such notice. If the indemnifying party,
within 10 days after notice of any such claim, fails to defend such claim, the
indemnified party will (upon further notice to the indemnifying party) have the
right to undertake the defense, compromise or settlement of such claim on behalf
of and for the account and risk of indemnifying party.

          (b) Anything in this Section 8.4 to the contrary notwithstanding, (i)
an indemnified party shall have the right, at its own cost and expense, to
participate in the defense, compromise or settlement of such claim, (ii) the
indemnifying party shall not, without the written consent of the indemnified
party, settle or compromise any claim or consent to the entry of any judgment
(x) which does not include as an unconditional term thereof the giving by the
claimant or the plaintiff to the indemnified party a release from all liability
in respect of such claim or (y) as a result of which injunctive or other
equitable relief would be imposed against the indemnified party, and (iii) the
indemnified party shall have the right to control the defense or settlement of
that portion of any claim which seeks an order, injunction or other equitable
relief against the indemnified party which, if successful, could materially
interfere with the business, operations, assets, financial condition or
prospects of the indemnified party; provided, however, that in connection with
the defense or settlement of the portion of such claim which seeks equitable
relief, the indemnified party shall cooperate with the indemnifying party and
use its reasonable best efforts to limit the liability of the indemnifying party
for the damages portion of such claim.

                                   ARTICLE IX

                                  MISCELLANEOUS

          SECTION 9.1 NOTICES.

          All notices required to be given hereunder shall be in writing and
shall be deemed to be duly given if personally delivered, telecopied and
confirmed, or mailed by certified mail, return receipt requested, or overnight
delivery service with proof of receipt maintained, at the following address (or
any other address that any such party may designate by written notice to the
other parties):

                                       28
<PAGE>

          Bill Barrett Corporation
          1099 18th Street, Suite 2300
          Denver, Colorado 80202
          Facsimile:  (303) 291-0420

If to any Investor, at his address as set forth on Annex A of this Agreement.

Any such notice shall, if delivered personally, be deemed received upon
delivery; shall, if delivered by telecopy, be deemed received on the first
business day following confirmation; shall, if delivered by overnight delivery
service, be deemed received the first business day after being sent; and shall,
if delivered by mail, be deemed received upon the earlier of actual receipt
thereof or five business days after the date of deposit in the United States
mail.

          SECTION 9.2 ENTIRE AGREEMENT.

          This Agreement, together with the Exhibits and Annexes and other
writings referred to herein or delivered pursuant hereto, constitute the entire
agreement between the parties hereto with respect to the subject matter hereof
and supersedes all prior agreements and understandings, both written and oral,
between the parties with respect to the subject matter hereof.

          SECTION 9.3 BINDING EFFECT; ASSIGNMENT; NO THIRD PARTY BENEFIT.

          This Agreement shall be binding upon and inure to the benefit of the
parties hereto and their respective heirs, legal representatives, successors and
permitted assigns. Except as otherwise expressly provided in this Agreement or
the Stockholders' Agreement, neither this Agreement nor any of the rights,
interests, or obligations hereunder shall be assigned by (i) the Company to any
person without the prior written consent of the Investors, and (ii) any Investor
to any person, without the prior written consent of the Company, which consent
shall not be unreasonably withheld, except that any Investor may assign to any
affiliate of such Investor the rights, interests or obligations hereunder of
such Investor, upon notice to the Company; provided that no such assignment
shall relieve such Investor of its obligations hereunder unless approved by the
Board of Directors of the Company (which approval shall not be unreasonably
withheld), in which case the Investor shall be relieved of its obligations
hereunder to the extent of such assignment. Notwithstanding the provisions set
forth in clause (ii) of the immediately preceding sentence, any Investor,
together with all affiliates of such Investor (an "Investor Group"), may,
without the consent of the Company's Board of Directors, assign or otherwise
transfer its rights and obligations under this Agreement to any affiliate of
such Investor Group (including, for J.P. Morgan, J.P. Morgan Global Investors,
L.P., a Delaware limited partnership) and to any other related parallel and
alternative investment vehicles (collectively, the "Group Fund Entities"),
provided that such Investor provides the Company with written notice of any such
assignment or transfer within 10 days of the date thereof and such Group Fund
Entity assumes in writing all liabilities and obligations under this Agreement,
the Stockholders' Agreement and the Registration Rights Agreement to the extent
of such assignment, and provided,

                                       29
<PAGE>

further, that any such assignment or transfer by any member of an Investor Group
from or after 90 days from the date hereof that results in the aggregate of all
assignments or transfers by members of such Investor Group exceeding 50% of the
aggregate rights and obligations originally held by members of such Investor
Group shall require the advance written consent of the Company (such consent not
to be unreasonably withheld). The Company hereby agrees to release any such
transferring Investor from any liability that may arise from or relate to any of
the obligations assigned or otherwise transferred by such Investor to the
related Group Fund Entities in accordance with the terms of this Section 9.3.
Nothing in this Agreement, express or implied, is intended to or shall confer
upon any person other than the parties hereto, and their respective heirs, legal
representatives, successors, and permitted assigns, any rights, benefits, or
remedies of any nature whatsoever under or by reason of this Agreement.

          SECTION 9.4 SEVERABILITY.

          If any provision of this Agreement is held to be unenforceable, this
Agreement shall be considered divisible and such provision shall be deemed
inoperative to the extent it is deemed unenforceable, and in all other respects
this Agreement shall remain in full force and effect; provided, however, that if
any such provision may be made enforceable by limitation thereof, then such
provision shall be deemed to be so limited and shall be enforceable to the
maximum extent permitted by applicable law.

          SECTION 9.5 CALIFORNIA CORPORATE SECURITIES LAW.

          THE SALE OF THE SECURITIES WHICH ARE THE SUBJECT OF THIS AGREEMENT HAS
NOT BEEN QUALIFIED WITH THE COMMISSIONER OF CORPORATIONS OF THE STATE OF
CALIFORNIA AND THE ISSUANCE OF SUCH SECURITIES OR THE PAYMENT OR RECEIPT OF ANY
PART OF THE CONSIDERATION FOR SUCH SECURITIES PRIOR TO SUCH QUALIFICATION IS
UNLAWFUL, UNLESS THE SALE OF SECURITIES IS EXEMPT FROM QUALIFICATION BY SECTION
25100, 25102 OR 25105 OF THE CALIFORNIA CORPORATIONS CODE. THE RIGHTS OF ALL
PARTIES TO THIS AGREEMENT ARE EXPRESSLY CONDITIONED UPON SUCH QUALIFICATION
BEING OBTAINED, UNLESS THE SALE IS SO EXEMPT.

          SECTION 9.6 GOVERNING LAW.

          THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED AND ENFORCED IN
ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK, WITHOUT REGARD TO THE
PRINCIPLES OF CONFLICTS OF LAWS THEREOF.

          SECTION 9.7 DESCRIPTIVE HEADINGS.

          The descriptive headings herein are inserted for convenience of
reference only, do not constitute a part of this Agreement, and shall not affect
in any manner the meaning or interpretation of this Agreement.

                                       30
<PAGE>

          SECTION 9.8 GENDER.

          Pronouns in masculine, feminine, and neuter genders shall be construed
to include any other gender, and words in the singular form shall be construed
to include the plural and vice versa, unless the context otherwise requires.

          SECTION 9.9 REFERENCES.

          All references in this Agreement to Sections and other subdivisions
refer to the Sections and other subdivisions of this Agreement unless expressly
provided otherwise. The words "this Agreement," "herein," "hereof," "hereby,"
"hereunder" and words of similar import refer to this Agreement as a whole and
not to any particular subdivision unless expressly so limited. Whenever the
words "include," "includes" and "including" are used in this Agreement, such
words shall be deemed to be followed by the words "without limitation." Each
reference herein to an Exhibit or Annex refers to the item identified separately
in writing by the parties hereto as the described Exhibit or Annex to this
Agreement. All Exhibits and Annexes are hereby incorporated in and made a part
of this Agreement as if set forth in full herein.

          SECTION 9.10 INJUNCTIVE RELIEF.

          The parties hereto acknowledge and agree that irreparable damage would
occur in the event any of the provisions of this Agreement were not performed in
accordance with their specific terms or were otherwise breached. It is
accordingly agreed that the parties shall be entitled to an injunction or
injunctions to prevent breaches of the provisions of this Agreement, and shall
be entitled to enforce specifically the provisions of this Agreement, in any
court of the United States or any state thereof having jurisdiction, in addition
to any other remedy to which the parties may be entitled under this Agreement or
at law or in equity.

          SECTION 9.11 CONSENT TO JURISDICTION.

                  (a) The parties hereto hereby irrevocably submit to the
exclusive jurisdiction of the courts of the State of New York and the federal
courts of the United States of America located in New York, and appropriate
appellate courts therefrom, over any dispute arising out of or relating to this
Agreement or any of the transactions contemplated hereby, and each party hereby
irrevocably agrees that all claims in respect of such dispute or proceeding may
be heard and determined in such courts. The parties hereby irrevocably waive, to
the fullest extent permitted by applicable law, any objection which they may now
or hereafter have to the laying of venue of any dispute arising out of or
relating to this Agreement, the Stockholders' Agreement, the Registration Rights
Agreement or any of the transactions contemplated hereby brought in such court
or any defense of inconvenient forum for the maintenance of such dispute. Each
of the parties hereto agrees that a judgment in any such dispute may be enforced
in other jurisdictions by suit on the judgment or in any other manner provided
by law. This consent to jurisdiction is being given solely for purposes of this
Agreement, the Stockholders' Agreement and the Registration Rights Agreement and
is not intended to,

                                       31
<PAGE>

and shall not, confer consent to jurisdiction with respect to any other dispute
in which a party to this Agreement may become involved.

                  (b) Each of the parties hereto hereby consents to process
being served by any party to this Agreement in any suit, action, or proceeding
of the nature specified in subsection (a) above by the mailing of a copy thereof
in the manner specified by the provisions of Section 9.1.

                  (c) EACH OF THE PARTIES HERETO HEREBY IRREVOCABLY WAIVES ALL
RIGHT TO TRIAL BY JURY IN ANY ACTION, PROCEEDING OR COUNTERCLAIM ARISING OUT OF
OR RELATING TO THIS AGREEMENT.

          SECTION 9.12 AMENDMENT.

          The provisions of this Agreement may be amended, waived or modified
only with the written consent of the Company and the holders of more than 50% of
the Series B Preferred, or if the Series B Preferred has been converted to
Common Stock, then the holders of more than 50% of the Common Stock not
previously sold to the public that is issued or issuable upon conversion of the
Series B Preferred (other than Defaulting Investors) (the "Requisite
Stockholders"); provided, however, that any vote requiring Requisite
Stockholders' approval which adversely affects the rights of any Investor
(including a Defaulting Investor), in its capacity as an Investor, without
adversely affecting the rights of all Investors, in their capacities as
Investors, or that increases the Capital Commitment of any Investor or imposes
any other material obligation on any Investor shall not be effective as to such
Investor without its prior written consent.

          SECTION 9.13 EFFECT OF AMENDMENT OR WAIVER.

          Each Investor acknowledges that by the operation of Section 9.12
hereof the Requisite Stockholders will have the right and power to diminish or
eliminate all rights of such Investor under this Agreement.

          SECTION 9.14 WAIVER.

          No failure or delay by a party hereto in exercising any right, power,
or privilege hereunder shall operate as a waiver thereof nor shall any single or
partial exercise thereof preclude any other or further exercise thereof or the
exercise of any other right, power, or privilege.

          SECTION 9.15 COUNTERPARTS.

          This Agreement may be executed by the parties hereto in any number of
counterparts, each of which shall be deemed an original, but all of which shall
constitute one and the same agreement. Each counterpart may consist of a number
of copies hereof each signed by less than all, but together signed by all, the
parties hereto.

                                       32
<PAGE>

          SECTION 9.16 ADJUSTMENTS FOR STOCK SPLITS, ETC.

          Wherever in this Agreement there is a reference to a specific number
of shares of stock of the Company of any class or series, or a price per share
of such stock, or consideration received in respect of such stock, then, upon
the occurrence of any subdivision, combination, or stock dividend of such class
or series of stock, the specific number of shares or the price so referenced in
this Agreement shall automatically be proportionally adjusted to reflect the
effect on the outstanding shares of such class or series of stock by such
subdivision, combination, or stock dividend.

                                       33
<PAGE>

          IN WITNESS WHEREOF, the parties have executed this Agreement as of the
date first above written.

                                           COMPANY:

                                           BILL BARRETT CORPORATION

                                           By:    /s/ J. Frank Keller
                                                  ------------------------------
                                           Name:  J. Frank Keller
                                           Title: Chief Operating Officer

                                       34
<PAGE>

                               INVESTOR:

                               COLORADO PUBLIC EMPLOYEE RETIREMENT ASSOCIATION

                               By: /s/ Norman Benedict
                                   ---------------------------------------------
                                   Norman Benedict
                                   Deputy Executive Director of Investments

<PAGE>

                               INVESTOR:

                               GS CAPITAL PARTNERS 2000, L.P.

                               BY:      GS Advisors 2000, L.L.C.,
                                        its General Partner

                               By:      /s/ John E. Bowman
                                        ----------------------------------------
                               Name:    John E. Bowman
                               Title:   Vice President

                               GSCP 2000 OFFSHORE BBOG HOLDING, L.P.

                               BY:      GS Capital Partners 2000 Offshore, L.P.,
                                        its General Partner

                               BY:      GS Advisors 2000, L.L.C.,
                                        its General Partner

                               By:      /s/ John E. Bowman
                                        ----------------------------------------
                               Name:    John E. Bowman
                               Title:   Vice President

                               GSCP 2000 GMBH BBOG HOLDING, L.P.

                               BY:      GSCP 2000 GmbH BBOG Holding I,
                                        its General Partner

                               By:      /s/ John E. Bowman
                                        ----------------------------------------
                               Name:    John E. Bowman
                               Title:   Vice President

                               GS CAPITAL PARTNERS 2000 EMPLOYEE FUND, L.P.

                               BY:      GS Employee Funds 2000 GP, L.L.C.,
                                        its General Partner

                               By:      /s/ John E. Bowman
                                        ----------------------------------------
                               Name:    John E. Bowman
                               Title:   Vice President

<PAGE>

                               STONE STREET FUND 2000, L.P.

                               BY:      Stone Street 2000, L.L.C.,
                                        its General Partner

                               By:      /s/ John E. Bowman
                                        ----------------------------------------
                               Name:    John E. Bowman
                               Title:   Vice President

                               STONE STREET BBOG HOLDING

                               By:      /s/ John E. Bowman
                                        ----------------------------------------
                               Name:    John E. Bowman
                               Title:   Vice President

                               GOLDMAN SACHS DIRECT INVESTMENT FUND 2000, L.P.

                               BY:      GS Employee Funds 2000 GP, L.L.C.,
                                        its General Partner

                               By:      /s/ John E. Bowman
                                        ----------------------------------------
                               Name:    John E. Bowman
                               Title:   Vice President

<PAGE>

                               INVESTOR:

                               J.P. MORGAN PARTNERS (BHCA), L.P.

                               BY:      JPMP MASTER FUND MANAGER, L.P.,
                                        ITS GENERAL PARTNER

                               BY:      JPMP CAPITAL CORP.,
                                        ITS GENERAL PARTNER

                               By:      /s/ Christopher Behrens
                                        ----------------------------------------
                                        Christopher Behrens
                                        Managing Director

<PAGE>

                               INVESTOR:

                               PALANTIR PARTNERS LP

                               BY:      PALANTIR ASSOCIATES LLC
                                        its General Partner

                               By:      /s/ Glenn Doshay
                                        ----------------------------------------
                                        Glenn Doshay
                                        President

                               THE DOSHAY FAMILY TRUST OF 1999

                               By:      /s/ Glenn Doshay
                                        ----------------------------------------
                                        Glenn Doshay
                                        Trustee

<PAGE>

                               INVESTOR:

                               STATE FARM MUTUAL AUTOMOBILE INSURANCE COMPANY

                               By:      /s/ John Conklin
                                        ----------------------------------------
                                        John Conklin
                                        Vice President - Common Stocks

                               By:      /s/ John Elterich
                                        ----------------------------------------
                                        John Elterich
                                        Assistant Secretary

<PAGE>

                               INVESTOR:

                               WARBURG PINCUS PRIVATE EQUITY VIII, L.P.

                               BY:      WARBURG PINCUS & CO.,
                                        AS GENERAL PARTNER

                               By:      /s/ Jeffrey A. Harris
                                        ----------------------------------------
                                        Jeffrey A. Harris, Partner<PAGE>
                                                                    EXHIBIT 10.4

                           PURCHASE AND SALE AGREEMENT

                                     BETWEEN

                           WASATCH OIL & GAS, LLC AND

                           WASATCH GAS GATHERING, LLC

                                    AS SELLER

                                       AND

                            BILL BARRETT CORPORATION

                                    AS BUYER

                          DATED EFFECTIVE APRIL 1, 2002

<PAGE>

                           PURCHASE AND SALE AGREEMENT

                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                           Page
                                                                           ----
<S>                                                                        <C>
RECITALS..................................................................  1

ARTICLE 1            PURCHASE AND SALE....................................  1

   1.1      PURCHASE AND SALE.............................................  1
   1.2      ASSETS........................................................  1
   1.3      PROPERTY NOT BEING SOLD.......................................  3
   1.4      EFFECTIVE TIME................................................  3

ARTICLE 2            PURCHASE PRICE.......................................  3

   2.1      PURCHASE PRICE................................................  3
   2.2      PERFORMANCE GUARANTEE DEPOSIT.................................  3
   2.3      ALLOCATION OF THE PURCHASE PRICE..............................  3
   2.4      ADJUSTMENT TO PURCHASE PRICE..................................  3

ARTICLE 3            BUYER'S INSPECTION...................................  5

   3.1      ACCESS TO RECORDS.............................................  5
      (a)      Access.....................................................  5
      (b)      No Representation or Warranty..............................  5
   3.2      ACCESS TO PROPERTIES..........................................  5
      (a)      Access.....................................................  5
      (b)      Insurance..................................................  6

ARTICLE 4            TITLE MATTERS........................................  6

   4.1      DEFENSIBLE TITLE TO THE PROPERTIES............................  6
      (a)      Defensible Title...........................................  6
      (b)      Permitted Encumbrances.....................................  6
      (c)      Title Defect...............................................  7
      (d)      Allocated Value............................................  8
   4.2      PURCHASE PRICE ADJUSTMENTS FOR DEFECTIVE INTERESTS............  8
      (a)      Defective Interest.........................................  8
      (b)      Notice of Defective Interest...............................  8
      (c)      Defect Adjustments and Exclusions..........................  8
      (d)      Defect Value...............................................  8
   4.3      CASUALTY LOSS.................................................  9

ARTICLE 5            ENVIRONMENTAL MATTERS................................  9

   5.1      ENVIRONMENTAL REPRESENTATION AND STANDARD.....................  9
      (a)      Environmental Law(s).......................................  9
   5.2      ENVIRONMENTAL NOTICE.......................................... 10
   5.3      REMEDY FOR ENVIRONMENTAL BREACH............................... 10
</TABLE>

<PAGE>

<TABLE>
<S>                                                                         <C>
      (a)      Remedy.....................................................  10
      (b)      Exclusion of Affected Asset................................  10
      (c)      Exhibit F Matters..........................................  10
   5.4      LIMITATIONS ON SELLER'S OBLIGATIONS...........................  11
   5.5      ENVIRONMENTAL INDEMNITY.......................................  11
   5.6      APPLICABILITY OF OTHER PROVISION..............................  11
   5.7      BUYER'S REPORTS...............................................  11
   5.8      EXCLUSIVE REMEDY..............................................  12
   5.9      ENVIRONMENTAL DUE DILIGENCE ACTIVITIES........................  12

ARTICLE 6            SELLER'S REPRESENTATIONS AND WARRANTIES..............  12

   6.1      ORGANIZATION AND STANDING.....................................  12
   6.2      POWER.........................................................  12
   6.3      AUTHORIZATION AND ENFORCEABILITY..............................  12
   6.4      LIABILITY FOR BROKERS' FEES...................................  13
   6.5      NO BANKRUPTCY.................................................  13
   6.6      LITIGATION....................................................  13
   6.7      MATERIAL AGREEMENTS...........................................  13
   6.8      TAXES.........................................................  13
   6.9      TAX PARTNERSHIPS..............................................  13
   6.10     LEASE MAINTENANCE.............................................  14
   6.11     GAS IMBALANCES................................................  14
   6.12     COMPLIANCE WITH LAWS, ETC.....................................  14
   6.13     OTHER BURDENS.................................................  14
   6.14     CONDITION OF EQUIPMENT........................................  14
   6.15     NO CHANGES....................................................  14
   6.16     STATEMENT OF COUNSEL..........................................  15

ARTICLE 7            BUYER'S REPRESENTATIONS AND WARRANTIES...............  15

   7.1      ORGANIZATION AND STANDING.....................................  15
   7.2      POWER.........................................................  15
   7.3      AUTHORIZATION AND ENFORCEABILITY..............................  15
   7.4      LIABILITY FOR BROKERS' FEES...................................  15
   7.5      LITIGATION....................................................  15
   7.6      SECURITIES LAWS; SOPHISTICATION OF BUYER......................  15
   7.7      HOLDING COMPANY...............................................  16
   7.8      FINANCIAL RESOURCES...........................................  16
   7.9      INDEPENDENT EVALUATION........................................  16

ARTICLE 8            COVENANTS AND AGREEMENTS.............................  16

   8.1      COVENANTS AND AGREEMENTS OF SELLER............................  16
      (a)      Operations Prior to Closing................................  16
      (b)      Restriction on Operations..................................  17
      (c)      Marketing..................................................  17
      (d)      Consents...................................................  17
      (e)      Status.....................................................  18
      (f)      Notices of Claims..........................................  18
      (g)      Compliance with Laws.......................................  18
</TABLE>

<PAGE>

<TABLE>
<S>                                                                             <C>
      (h)      Insurance......................................................  18
      (i)   Resolution of Retained Matters....................................  18
   8.2      COVENANTS AND AGREEMENTS OF BUYER.................................  18
      (a)      Status.........................................................  18
      (b)      Bonding; Insurance.............................................  18
   8.3      COVENANTS AND AGREEMENTS OF THE PARTIES...........................  18
      (a)      Government Reviews and Filings.................................  18
      (b)      Data and Information...........................................  19
      (c)      Lavinia Well...................................................  19

ARTICLE 9            TAX MATTERS..............................................  20

   9.1      APPORTIONMENT OF TAX LIABILITY....................................  20
   9.2      CALCULATION OF TAX LIABILITY......................................  20
   9.3      TAX REPORTS AND RETURNS...........................................  20
   9.4      SALES AND TRANSFER TAXES..........................................  20

ARTICLE 10           CONDITIONS TO CLOSING....................................  21

   10.1     SELLER'S CONDITIONS...............................................  21
   10.2     BUYER'S CONDITIONS................................................  21

ARTICLE 11           RIGHT OF TERMINATION AND ABANDONMENT.....................  22

   11.1     TERMINATION.......................................................  22
   11.2     LIABILITIES UPON TERMINATION......................................  22
      (a)      Buyer's Breach.................................................  22
      (b)      Seller's Breach................................................  22
      (c)      Termination Without Further Liability..........................  22

ARTICLE 12           CLOSING..................................................  23

   12.1     DATE OF CLOSING...................................................  23
   12.2     PLACE OF CLOSING..................................................  23
   12.3     CLOSING OBLIGATIONS...............................................  23

ARTICLE 13           POST-CLOSING OBLIGATIONS.................................  24

   13.1     POST-CLOSING ADJUSTMENTS..........................................  24
   13.2     RECORDS...........................................................  24
   13.3     TRANSFER AND RECORDING FEES.......................................  24
   13.4     ADDITIONAL PROCEEDS AND INVOICES..................................  25
   13.5     FURTHER ASSURANCES................................................  25
   13.6     SUSPENSE FUNDS....................................................  25

ARTICLE 14           ASSUMPTION OF OBLIGATIONS AND INDEMNIFICATION............  25

   14.1     ASSUMPTION OF LIABILITIES AND OBLIGATIONS BY BUYER................  25
   14.2     BUYER'S INDEMNIFICATION OF SELLER.................................  25
   14.3     LIABILITIES AND OBLIGATIONS RETAINED BY SELLER....................  26
   14.4     SELLER'S INDEMNIFICATION OF BUYER.................................  26
   14.5     SELLER'S ADDITIONAL OBLIGATIONS RELATING TO THE RETAINED MATTERS..  26
      (a)      Seller's Retention of Obligations..............................  26
      (b)      Seller's Indemnification of Buyer..............................  26
</TABLE>

<PAGE>

<TABLE>
<S>                                                                         <C>
      (c)      Settlement of Claims.......................................  27
      (d)      Escrow Account.............................................  27
      (e)      No Limitations.............................................  27
      (f)      Release of Buyer...........................................  27
      (g)      Survival...................................................  27
   14.6     RESERVATION AS TO NON-PARTIES.................................  28
   14.7     PARENT GUARANTEE; JOINT AND SEVERAL LIABILITY.................  28

ARTICLE 15           MISCELLANEOUS........................................  28

   15.1     EXHIBITS......................................................  28
   15.2     EXPENSES......................................................  28
   15.3     NOTICES.......................................................  28
   15.4     AMENDMENTS....................................................  29
   15.5     ASSIGNMENT....................................................  29
   15.6     ANNOUNCEMENTS.................................................  29
   15.7     HEADINGS......................................................  29
   15.8     COUNTERPARTS..................................................  29
   15.9     REFERENCES....................................................  29
   15.10       GOVERNING LAW..............................................  29
   15.11       ENTIRE AGREEMENT...........................................  29
   15.12       BINDING EFFECT.............................................  30
   15.13       SURVIVAL...................................................  30
   15.14       CLOSING CONDITIONS.........................................  30
   15.15       NO THIRD-PARTY BENEFICIARIES...............................  30
   15.16       LIKE-KIND EXCHANGE.........................................  30
   15.17       JOINT AND SEVERAL LIABILITY................................  30
   15.18       INFORMATION PROVIDED BY SELLER.............................  30
   15.19       DISCLAIMER OF REPRESENTATIONS AND WARRANTIES...............  31
   15.20       DISPUTE RESOLUTION.........................................  32
   15.21       LIMITATION OF LIABILITY....................................  32
</TABLE>

<PAGE>

                                    EXHIBITS

<TABLE>
<CAPTION>
                                                          Section
 Exhibit                Description                    where Defined
 -------                -----------                    -------------
<S>          <C>                                       <C>
    A        Leases/Assets                                1.2

    B        Wells/Allocated Value                        1.2(b)/2.3

    C-1      Gas Gathering System Facilities              1.2(c)

    C-2      Map of Gas Gathering System                  1.2(c)

    D        Form of Assignment,
             Bill of Sale and Conveyance                  12.3(a)

    E        FIRPTA Certificate                           12.3(i)

    F        Environmental Matters                        5.1

    G        Litigation                                   6.6

    H        Excluded Equipment                           1.2(f)

    I        Material Agreements                          1.2(e)

    J        Sheriff's Deed                               14.5(a)

    K        Escrow Agreement                             14.5(d)
</TABLE>

<PAGE>

                           PURCHASE AND SALE AGREEMENT

            THIS PURCHASE AND SALE AGREEMENT ("Agreement"), dated April ___,
2002 is by and between Wasatch Oil & Gas LLC, a Utah limited liability company,
and Wasatch Gas Gathering, LLC, a Utah limited liability company, whose address
is P.O. Box 699, Farmington, Utah 84025-0699 (jointly "Wasatch" or "Seller") and
Bill Barrett Corporation, a Maryland corporation, whose address 1099 18th
Street, Suite 2300, Denver, Colorado 80202 ("Buyer").

                                    RECITALS

            A.    Seller owns and has decided to sell certain of its real and
personal property interests in certain oil and gas properties located in Carbon
and Duchesne Counties, Utah, as described in Section 1.2 below (collectively,
the "Assets").

            B.    Buyer has conducted an independent investigation of the
nature, extent and potential of the Assets and desires to purchase the Assets
pursuant to the terms of this Agreement.

                                    AGREEMENT

            In consideration of the mutual promises contained herein and other
good and valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, Buyer and Seller agree as follows:

                                    ARTICLE 1

                                PURCHASE AND SALE

            1.1   PURCHASE AND SALE. Seller agrees to sell and Buyer agrees to
purchase the Assets pursuant to the terms of this Agreement.

            1.2   ASSETS. The interest in and to the real property and the other
types of property associated therewith as described in this Section 1.2 may be
referred to collectively as the "Assets." The Assets are comprised of the
following:

                  (a)   All of Seller's right, title and interest in and to the
oil and gas leases specifically described in Exhibit A (collectively, the
"Leases"), the royalties, overriding royalties, net profits interests,
production payments and other interests, if any, owned by Seller burdening the
Leases, and any and all right, title and interest in and to the oil, gas and all
other hydrocarbons in, on or under the lands covered by the Leases (the "Lands")
and other hydrocarbons and products, whether liquid or gaseous, produced from
such Leases or Lands ("Hydrocarbons") after the Effective Time and all other
minerals of whatever nature in, on or under the Leases and Lands and lands
pooled or unitized therewith.

                  (b)   The oil and gas wells located on the Leases and Lands,
or lands pooled or unitized therewith, including without limitation, the oil and
gas wells specifically described in Exhibit B, whether producing or
non-producing and whether fully or properly described or not, (the

<PAGE>

"Wells"), all injection and disposal wells on the Leases or Lands, and all
personal property and equipment associated with the Wells as of the Effective
Time.

                  (c)   The gas gathering system related to the Leases and the
Lands, as depicted and described on Exhibit C-1 and C-2, including without
limitation all of the equipment and other personal property, fixtures,
improvements, permits, licenses, approvals, servitudes, rights-of-way and
easements used in connection with the system (collectively the "Gas Gathering
System").

                  (d)   The rights, to the extent transferable, in and to all
existing and effective unitization, pooling and communitization agreements,
declarations and orders, and the properties covered and the units created
thereby to the extent that they relate to or affect any of Seller's properties
and interests described in Sections 1.2(a) and (b) or the production of
Hydrocarbons, if any, attributable to said properties and interests after the
Effective Time.

                  (e)   The rights, to the extent transferable, in and to
existing and effective oil, gas, liquids, condensate, casinghead gas and natural
gas sales, purchase, exchange, gathering, transportation and processing
contracts, operating agreements, balancing agreements, joint venture agreements,
partnership agreements, farmout agreements and other contracts, agreements and
instruments, insofar only as they relate to any of Seller's properties and
interests described in Sections 1.2(a), (b) (c) and (d), excluding, however, any
insurance contracts (the "Agreements"). The Agreements that are material to the
ownership and operation of the Assets are referred to herein as the "Material
Agreements" and are set forth in Exhibit I.

                  (f)   With the exception of the equipment listed on Exhibit H,
which is excluded from this Agreement (the "Excluded Equipment"), all of the
personal property, fixtures, improvements, permits, licenses, approvals,
servitudes, rights-of-way and easements, including, without limitation the
rights of way and easements set forth on Exhibit A, surface leases and other
surface rights (including, but not limited to, any wells, tanks, boilers,
buildings, injection facilities, saltwater disposal facilities, compression
facilities, gathering systems, other appurtenances and facilities) located on or
used in connection with or otherwise related to the exploration for or
production, gathering, treatment, processing, storing, sale or disposal of
Hydrocarbons or water produced from the properties and interests described in
Sections 1.2(a) through (e) to the extent that they are located on or used in
the operation of the Assets as of the Effective Time, and all contract rights
(including rights under leases to third parties) related thereto.

                  (g)   The files, records, data and information relating to the
items described in Sections 1.2(a) through (f) maintained by Seller (the
"Records"), including without limitation, accounting files to the extent related
to the Assets, lease files, land files, well files, gas, oil and other
hydrocarbon sales contract files, gas processing files, division order files,
abstracts, title opinions, all electronic files directly related to the Assets,
AFEs, geological and seismic data to the extent such seismic data can be
transferred to Seller, and all other information of every type related
exclusively or primarily to any of the Assets, but excluding the following: (i)
all of Seller's internal appraisals and interpretive data related to the Assets,
(ii) all information and data under contractual restrictions on assignment,
(iii) all privileged information, (iv) Seller's corporate, financial, employee
and general tax records that do not relate exclusively to the Assets and (v) all
accounting files that do not relate to the Assets.

                                      -2-
<PAGE>

            1.3   PROPERTY NOT BEING SOLD. THE OVERRIDING ROYALTY INTERESTS
PREVIOUSLY CONVEYED TO SELLER BY ASSIGNMENT OF OVERRIDING ROYALTY INTEREST
RECORDED IN BOOK 495 AT PAGES 588 AND 591, CARBON COUNTY, UTAH AND BOOK M297 AT
PAGE 348, DUCHESNE COUNTY, UTAH.

            1.4   EFFECTIVE TIME. The purchase and sale of the Assets shall be
effective as of April 1, 2002, at 7:00 a.m. Mountain Standard Time (the
"Effective Time").

                                    ARTICLE 2

                                 PURCHASE PRICE

            2.1   PURCHASE PRICE. The purchase price for the Assets shall be
Eight Million Fifty Thousand Dollars ($8,050,000.00) (the "Purchase Price"). At
Closing, Buyer shall pay Seller the Purchase Price, as adjusted pursuant to
Section 2.4.

            2.2   PERFORMANCE GUARANTEE DEPOSIT. Upon execution of this
Agreement, Buyer shall deliver to Seller a performance guarantee deposit by wire
transfer of immediately available funds equal to Eight Hundred Five Thousand
Dollars ($805,000.00) (the "Deposit"). The Deposit shall be credited to the
Purchase Price at Closing, or if this Agreement is terminated, shall be
distributed or retained pursuant to Article 11.

            2.3   ALLOCATION OF THE PURCHASE PRICE. The Purchase Price shall be
allocated among the Assets as set forth on Exhibit B. The value allocated to an
interest as set forth in Exhibit B may be referred to as the "Allocated Value"
for that interest.

            2.4   ADJUSTMENT TO PURCHASE PRICE. All Purchase Price adjustments
shall be made according to the factors described in this Section 2.4. The
Purchase Price shall be adjusted at Closing pursuant to the "Preliminary
Settlement Statement" prepared by Seller and submitted to Buyer five (5) days
prior to Closing for Buyer's comment and review. Buyer and Seller shall mutually
agree on the Preliminary Settlement Statement prior to Closing, with any
disagreements to be handled in the Final Settlement Statement and the dispute
resolution mechanism set forth in Section 13.1(b). The Preliminary Settlement
Statement shall set forth the Closing Amount and all Purchase Price adjustments
and associated calculations. The term "Closing Amount" means the Purchase Price
adjusted at Closing as provided in this Section 2.4, using the best information
available. After Closing, the Purchase Price shall be adjusted pursuant to the
Final Settlement Statement.

            For the purposes of this Agreement, the term "Capital/LOE/JIB
Expenses" shall mean all capital expenses, joint interest billings, lease rental
and maintenance costs, royalties, Taxes (as that term is defined in Article 9),
drilling expenses, workover expenses, geological, geophysical and other
exploration expenditures chargeable under applicable operating agreements
consistent with the standards established by the Council of Petroleum
Accountants Societies of North America ("COPAS") that are attributable to the
maintenance and operation of the Assets during the period in question.

                                      -3-
<PAGE>

            (a)   The Purchase Price shall be adjusted upward by the following:

                  (1)   the value of all of Seller's interest in merchantable
oil and other liquid hydrocarbons in storage tanks above the pipeline
connections at the Effective Time as shown by actual gauging reports that is
credited to the Assets, as applicable, such value to be the actual price
received upon sale, less applicable taxes and gravity adjustments deducted by
the purchaser of such oil or natural gas liquids;

                  (2)   the amount of all actual direct costs and expenses
attributable to the Assets during the period after the Effective Time,
including, without limitation the Capital/LOE/JIB Expenses incurred and paid by
Seller (and approved by Buyer, if such approval is required pursuant to Section
8.1) in accordance with generally accepted accounting principles consistently
applied in the oil and gas industry ("GAAP"); and

                  (3)   to the extent not covered in the preceding paragraph, an
amount equal to all prepaid expenses that are in accordance with GAAP,
attributable to all or any portion of the Assets during the period after the
Effective Time, which were paid by or on behalf of Seller, and which will inure
to the benefit of Buyer, including, without limitation, oil and gas lease and
rights-of-way rentals, applicable insurance costs, prepaid utility charges,
equipment rentals, and prepaid Taxes (such Taxes to be apportioned pursuant to
Article 9).

            (b)   The Purchase Price shall be adjusted downward by the
following:

                  (1)   proceeds received by Seller (net of applicable taxes and
royalties) after the Effective Time which are attributable, in accordance with
GAAP, to production from the Assets during the period after the Effective Time;

                  (2)   the amount of all Capital/LOE/JIB Expenses that remain
unpaid by Seller or that have been paid by Buyer that are attributable to the
period prior to the Effective Time;

                  (3)   an amount equal to the sum of all Defect Adjustments and
Exclusion Adjustments; and

                  (4)   the amount of the Deposit

            (c)   The Purchase Price may be adjusted downward or upward for (i)
the amount of all documented pipeline imbalances as of the Effective Time for
the account of Seller and (ii) as appropriate, by an amount equal to $1.50 per
MCF for any gas which Seller may be entitled to take or be obligated to deliver
in excess of its net revenue interest in the Wells as a result of
underproduction or overproduction by Seller from such Wells, such amount to be
determined as of the Effective Time. To the extent there is an upward or
downward adjustment for any pipeline imbalances, the Purchase Price shall be
adjusted upward or downward, as appropriate, based upon the first-of-the month
price of spot gas delivered to pipelines for the Questar system closest the
production, as reported in Inside F.E.R.C.'s Gas Market Report for the month in
which the Effective Time occurs times the net overdelivery imbalance in MMbtus.
In the event such publication shall cease to be published, the parties shall
select a comparable publication.

                                      -4-
<PAGE>

                                    ARTICLE 3

                               BUYER'S INSPECTION

            3.1   ACCESS TO RECORDS.

                  (a)   Access. Prior to Closing and subject to Section 8.3(b),
Seller will disclose and make available to Buyer and its representatives at
Seller's offices and during Seller's normal business hours, all Records as may
be reasonably requested by Buyer for the purpose of permitting Buyer to complete
its due diligence review. Seller shall permit Buyer to inspect the Records only
to the extent, in each case, that Seller may do so without violating legal
constraints or any obligation of confidence or other contractual commitment of
Seller to a third party. Subject to the consent and cooperation of third
parties, Seller will cooperate with Buyer in Buyer's reasonable efforts to
obtain, at Buyer's sole expense, such additional information relating to the
Wells and associated drilling and spacing units as Buyer may reasonably desire,
to the extent in each case that Seller may do so without violating legal
constraints or any obligation of confidence or other contractual commitment of
Seller to a third party.

                  (b)   No Representation or Warranty. The Records are files or
copies thereof that Seller has used or generated in its normal course of
business. SELLER MAKES NO WARRANTY OR REPRESENTATION OF ANY KIND, EITHER EXPRESS
OR IMPLIED, WRITTEN OR ORAL, AS TO ANY STATEMENTS, WRITTEN OR ORAL, OTHER THAN
THOSE CONTAINED IN THIS AGREEMENT, MADE REGARDING INTERPRETATION OF OR
CONCLUSIONS TO BE DRAWN FROM THE RECORDS, OR OF BUYER'S RIGHT TO RELY THEREON.
SELLER SHALL NOT HAVE ANY LIABILITY TO ANY PERSON OR ENTITY CLAIMING TO HAVE
RELIED THEREON EXCEPT AS AND TO THE EXTENT SELLER KNOWS THE SAME TO BE
INACCURATE OR INCOMPLETE IN ANY MATERIAL RESPECT. Buyer acknowledges that any
conclusions drawn from the Records are the result of its own independent review
and judgment.

            3.2   ACCESS TO PROPERTIES.

                  (a)   Access. After the execution of this Agreement, upon
advance notice, Seller will grant Buyer and/or Buyer's authorized
representatives, agents and employees during reasonable business hours,
reasonable access to the Assets to allow Buyer to conduct, at Buyer's sole risk
and expense, on-site inspections and environmental assessments of the Wells and
Equipment, copies of which, inclusive of supporting data and whether in draft or
final form, shall be provided to Seller at the same time provided to Buyer. In
connection with such on-site inspections, Buyer agrees to not unreasonably
interfere with the normal operation of the Assets. Buyer shall repair, without
delay and at its own cost and expense, and hold Seller harmless from, any damage
to any of the Assets which may be caused by Buyer's inspection of such Assets or
entrance on to any related property of the Seller. In connection with granting
such access, and, except to the extent that such claims are caused by the gross
negligence or willful misconduct of Seller, Buyer waives and releases all claims
against Seller, its directors, officers, employees, agents and representatives
for injury to, or death of persons or damage to property arising in any way from
the access afforded to Buyer hereunder or the activities of Buyer or its
employees on the Wells and Equipment, and Buyer agrees

                                      -5-
<PAGE>

to indemnify, defend and hold harmless Seller, its affiliates, directors,
officers, employees, agents and representatives from and against all such
claims.

                  (b)   Insurance. In connection with exercising its rights
under this Section 3.2 of access to any Well or associated drilling and spacing
unit, Buyer represents to Seller that it has in force and effect comprehensive
liability and property damage, automobile and workmen's compensation insurance
with respect to Buyer and its agents, in accordance with standard industry
practice.

                                    ARTICLE 4

                                  TITLE MATTERS

            4.1   DEFENSIBLE TITLE TO THE PROPERTIES.

                  (a)   Defensible Title. The term "Defensible Title" to the
Assets means such title of Seller that, subject to and except for the Permitted
Encumbrances: (i) entitles Seller to receive not less than the net revenue
interest ("NRI") for the depths or formations, if any, set forth for each Well
(unit interest or leasehold interest, as applicable) and Lease on Exhibit B;
(ii) obligates Seller to bear costs and expenses relating to the maintenance,
development, operation and the production of Hydrocarbons from each Well (unit
interest or leasehold interest, as applicable) in an amount not greater than the
working interest ("WI") therefore as set forth on Exhibit B; and (iii) is free
and clear of encumbrances, liens and defects that would create a material
impairment of use and enjoyment of or loss of interest in the affected property.

                  (b)   Permitted Encumbrances. The term "Permitted
Encumbrances" shall mean:

                        (1)   lessors' royalties, overriding royalties,
         overriding royalties owned by Seller as described in Section 1.3, net
         profits interests, production payments, reversionary interests and
         similar burdens, if the net cumulative effect of all such burdens does
         not operate to reduce the NRI for a particular Asset below that set
         forth on Exhibit B;

                        (2)   any preferential rights to purchase and required
         third party consents to assignments of contracts and similar agreements
         for which written waivers or consents are obtained prior to Closing;

                        (3)   liens for taxes or assessments not yet due or not
         yet delinquent or, if delinquent, that are being contested in good
         faith in the normal course of business;

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

                        (5)   rights of reassignment, to the extent any exist as
         of the date of this Agreement, upon the surrender or expiration of any
         lease;

                                      -6-
<PAGE>

                        (6)   easements, rights-of-way, servitudes, permits,
         surface leases and other rights with respect to surface operations, on,
         over or in respect of any of the properties or any restriction on
         access thereto and that do not materially interfere with the operation
         of the affected Asset;

                        (7)   such Title Defects as Buyer has waived;

                        (8)   the terms and conditions of the Material
         Agreements;

                        (9)   materialmen's, mechanics', repairmen's,
         employees', contractors', operators' or other similar liens or charges
         arising in the ordinary course of business incidental to construction,
         maintenance or operation of the Assets (i) if they have not been filed
         pursuant to law and the time for filing them has expired, (ii) if
         filed, they have not yet become due and payable or payment is being
         withheld as provided by law, or (iii) if their validity is being
         contested in good faith by appropriate action;

                        (10)  rights reserved to or vested in any governmental
         authority to control or regulate any of the Assets in any manner, and
         all applicable laws, rules, regulations and orders of general
         applicability in the area; and

                        (11)  liens arising under operating agreements,
         unitization and pooling agreements and production sales contracts
         securing amounts not yet due or, if due, being contested in good faith
         in the ordinary course of business.

                  (c)   Title Defect. The term "Title Defect" means any material
encumbrance, encroachment, irregularity, defect in or objection to real property
title, excluding Permitted Encumbrances, that alone or in combination with other
defects renders Seller's title less than Defensible Title. Notwithstanding the
foregoing, the following shall not be considered Title Defects:

                        (1)   defects based on lack of information in Seller's
files;

                        (2)   defects in the chain of title consisting of the
mere failure to recite marital status in a document or successors of heirship
proceedings in a document, unless Buyer provides affirmative evidence that such
failure or omission has resulted in another party's actual and superior claim of
title to the relevant Asset;

                        (3)   lack of a survey;

                        (4)   defects that have been cured by possession under
applicable statutes of limitation for adverse possession or for prescription;

                                      -7-
<PAGE>

                        (5) defects based on failure to record leases issued by
any state or the United States of America (or any assignments of record title or
operating rights in such leases), in the real property or other county records
of the county in which such Asset is located if such recordation is not
necessary to constitute constructive notice of such leases pursuant to
applicable statutes of limitation for adverse possession or prescription; and

                        (6)   the Retained Matters (as defined in Section 14.5).

                  (d)   Allocated Value. If an Asset has not been given an
Allocated Value, or if the Asset's Allocated Value is zero, Seller shall be
deemed to have Defensible Title to such Asset, without liability or obligation
thereof to Buyer by Seller.

            4.2   PURCHASE PRICE ADJUSTMENTS FOR DEFECTIVE INTERESTS. For the
purposes of this Section 4.2, the deductibles set forth below apply to the
aggregate of Seller's interests in the Assets are identified on Exhibit B.

                  (a)   Defective Interest. For the Assets, "Defective
Interests" means such Asset(s) affected by a Title Defect(s) that reduces the
Allocated Value of the affected Asset(s) by more than $25,000.00 in the
aggregate for all affected Assets (such amount to be net to Seller's interest,
and such amount to be called the "Title Deductible"). The amount by which the
Allocated Value(s) of the affected Asset(s) has been reduced by a Title
Defect(s) shall be calculated in accordance with Section 4.2(d) (the "Defect
Value").

                  (b)   Notice of Defective Interest. Buyer shall give Seller
written "Notice of Defective Interests" as soon as possible but no later than on
or before three (3) business days prior to Closing at 5:00 p.m., Mountain Time
(the "Title Defect Notice Date"). Such notice shall be in writing and inclusion
of the following elements shall be a condition precedent to the effectiveness of
the Notice of Defective Interests: (i) a description of the Defective Interests,
including Buyer's basis for such characterization, (ii) the Allocated Value of
the affected Asset, and (iii) the Defect Value and the computations upon which
Buyer's belief is based. If Buyer does not deliver a timely and valid Notice of
Defective Interests for a particular Asset, title to such Assets shall be deemed
to be Defensible Title.

                  (c)   Defect Adjustments and Exclusions. Subject to Sections
4.2(a) and (b), if an Asset is affected by Defective Interests, the Purchase
Price shall be reduced in accordance with Section 2.4 by the Defect Value (which
reduction shall be called a "Defect Adjustment") unless, (i) Buyer agrees to
waive the relevant Title Defect, (ii) the basis for treating such property as a
Defective Interest has been removed by Seller at its sole cost and expense prior
to the Closing Date, or (iii) Seller and Buyer reach a subsequent agreement
regarding cure of the Defective Interest prior to Closing. Provided, however
that, for purposes of Section 2.4, the Purchase Price shall be reduced by the
amount of the total Defect Values in excess of $25,000.00 (which amount is a
deductible, not a threshold).

                  (d)   Defect Value. In determining which portions of the
properties are Defective Interests, it is the intent of the parties to include,
to the extent possible, only that portion of the affected Asset (whether a Well,
unit or leasehold interest, as applicable) materially and adversely affected by
the defect or basis for such property being treated as a Defective Interest. The
Defect Value shall not exceed the Allocated Value of the Asset and shall be
determined by the parties in

                                      -8-
<PAGE>

good faith taking into account the Title Deductible per Title Defect and all
relevant factors, including, but not limited to, the following:

                        (1)   The Allocated Value of the affected property;

                        (2)   The potential or actual reduction in the warranted
         NRI of the Defective Interest, or the potential or actual increase in
         the warranted WI to the extent such increase is not accompanied by a
         corresponding increase in NRI;

                        (3)   If the Title Defect represents only a possibility
         of title failure, the probability that such failure will occur;

                        (4)   The legal effect of the Title Defect; and

                        (5)   If the Title Defect is a lien or encumbrance on
         the property, the cost of removing such lien or encumbrance; provided
         however, there shall be no Title Deductible for a Title Defect which is
         a lien.

            4.3   CASUALTY LOSS. Prior to Closing, if a portion of the Assets is
destroyed by fire or other casualty, is taken or threatened to be taken in
condemnation or under the right of eminent domain (a "Casualty Loss"), Buyer
shall purchase the Asset at Closing for the Allocated Value of the Asset reduced
by the estimated cost to repair such Asset (with equipment of similar utility)
up to the Allocated Value thereof (the reduction being the "Net Casualty Loss")
and Seller shall retain all of Seller's rights to any insurance payments, awards
or other payments from third parties arising out of the Casualty Loss.

                                    ARTICLE 5

                              ENVIRONMENTAL MATTERS

            5.1   ENVIRONMENTAL REPRESENTATION AND STANDARD. Seller represents
that to its best knowledge, and except for all matters listed on Exhibit F: (i)
in conducting operations on the Assets, Wasatch, as operator of the Assets, has
complied in all material respects with Environmental Laws, or if Wasatch is not
the operator of the Assets, the operator of the Assets has complied in all
material respects with Environmental Laws, (ii) there does not exist any
material litigation, binding arbitration, orders or proceedings under any
Environmental Law seeking money damages, injunctive relief, remedial action,
penalties, or cost recovery in connection with operations conducted on the
Assets, and (iii) there does not exist any material condition with respect to
the Assets which could reasonably be the basis for a claim of a violation under
Environmental Laws. The facts stated in the foregoing representation, but
without regard to Seller's knowledge, are referred to herein as the
"Environmental Standard." Seller shall have no liability for the breach of the
foregoing representation, or for the failure of the Environmental Standard to be
true, except to the extent provided in Section 5.3.

                  (a)   Environmental Law(s). "Environmental Law(s)" means
statutes, and the rules and regulations promulgated thereunder, compacts,
treaties, conventions, rules, regulations, codes, plans, requirements, criteria,
standards, orders, decrees, judgments, injunctions, notices or demand letters
issued, promulgated or entered by any federal, state or local governmental
entity

                                      -9-
<PAGE>

("Laws") relating to use, storage, emissions, discharges, cleanup, releases or
threatened releases of pollutants, contaminants, naturally occurring radioactive
materials ("NORM"), chemicals or industrial, toxic or hazardous substances
("Pollutants") on or into the environment (including without limitation ambient
air, oceans, waterways, wetlands, surface water, ground water (tributary and
non-tributary), land (surface or subsurface strata) or otherwise relating to the
manufacture, processing, distribution, use, treatment, storage, disposal,
transportation or handling of Pollutants. Environmental Laws does not include
laws concerning (i) restoration or reclamation that does not involve Pollutants;
(ii) Man Made Material Fibers ("MMMF"); (iii) plugging and abandonment of wells;
or (iv) employee health and safety.

            5.2   ENVIRONMENTAL NOTICE. On or before three (3) business days
prior to Closing at 5:00 p.m., Mountain Time, Buyer may give Seller notice (an
"Environmental Notice") of any fact or circumstance that evidences the material
breach of Seller's representation in Section 5.1, or that is materially in
conflict with the Environmental Standard for matters related to operations
(either, an "Environmental Breach"); provided, however, that Buyer hereby waives
its right to give Seller an Environmental Notice pertaining to the Gas Gathering
System, regardless of any such material breach and/or material conflict. An
Environmental Notice shall only be valid and effective, if and only if it
satisfies all of the following conditions precedent:

                  (a)   The Environmental Notice must be substantiated in good
faith by Buyer's environmental experts and supported by reasonable supporting
documentation; and

                  (b)   The Environmental Notice must state Buyer's good faith
estimate of the amount of Loss (as defined in Article 14) potentially to be
incurred by Buyer on account of the Environmental Breach.

            5.3   REMEDY FOR ENVIRONMENTAL BREACH. If Buyer gives a valid
Environmental Notice in accordance with Section 5.2, Seller may provide for one
of the remedies in Section 5.3(a) with respect to the Environmental Breach that
is the subject of such Environmental Notice, but each such remedy, and the
aggregate of all remedies shall be limited in accordance with Section 5.4.

                  (a)   Remedy. If Buyer delivers a valid Environmental Notice
to Seller, Seller, at its election, shall have the option of (i) remediating the
Environmental Breach to the satisfaction of Buyer or the appropriate state and
federal agencies having jurisdiction, or (ii) paying Buyer's good faith estimate
of the amount of all Losses associated with the Environmental Breach, and
thereafter, Buyer shall waive and indemnify Seller for all Losses associated
with such Environmental Breach, up to a maximum of the Allocated Value for the
affected Asset(s).

                  (b)   Exclusion of Affected Asset. For Assets affected by a
valid Environmental Notice delivered prior to Closing, if the cost associated
with the Loss which is reasonably expected to be incurred by Buyer under this
Article 5 with respect to an Asset after application of the limitations set
forth in Section 5.4, is greater than 20% of the Allocated Value of the
particular Asset, Seller may, at its option, exclude the Asset from this
Agreement, and the Purchase Price shall be reduced by the Allocated Value of
such Asset (an "Exclusion Adjustment").

                  (c)   Exhibit F Matters. Notwithstanding anything in this
Agreement to the contrary, Buyer's sole remedy and Seller's sole obligation
regarding the matters described on Exhibit F shall be as follows: Seller shall
obtain all necessary permits and/or remediate such matters

                                      -10-
<PAGE>

in order to be in compliance with Section 6.12, below, within ninety (90) days
after Closing, at Seller's sole cost and expense. Seller shall provide Buyer
with all permits and other documentation reasonably necessary to evidence such
compliance.

            5.4   LIMITATIONS ON SELLER'S OBLIGATIONS. Seller's obligations
under this Article 5 are limited as follows:

                  (a)   For valid Environmental Notices, and subject to the
aggregate limitations in Section 5.4(b), Seller's obligations shall only arise
if the Cleanup or Loss indemnification obligation to Buyer on account of an
Environmental Breach is expected to exceed a deductible of $50,000.00 net to
Seller's account per "Incident" or condition. If the Loss from an Environmental
Breach that is a spill, release, discharge, or emission (a "Release") of the
same substance that occurs or reoccurs in the same general contaminated area on
account of a singular cause or course of conduct, such a Release shall be
considered as a single Incident.

                  (b)   Seller's obligations shall apply only to the amount of
all Losses exceeding the deductible in Section 5.4(a) which also in the
aggregate exceed a deductible amount of $100,000.00 net to Seller's account;
provided, however, that Seller's aggregate liabilities under this Article 5
shall not exceed the aggregate of the Allocated Values of the affected Assets.

            5.5   ENVIRONMENTAL INDEMNITY. Except as expressly provided in this
Article 5, upon Closing, Buyer shall assume all risk, liability, obligation and
Loss in connection with, and shall defend, indemnify and save and hold harmless
Seller and its affiliates, officers, directors, shareholders, representatives,
employees, agents, successors, and assigns (collectively, "Indemnified
Parties"), forever from and against all Losses incurred by such Indemnified
Parties in connection with any Environmental Matter. "Environmental Matter"
shall mean the following matters arising in connection with the Assets
regardless of whether incurred with respect to events occurring prior to or
after the Effective Time: (i) the violation of, and compliance with past,
present and future laws relating to environmental matters, including
Environmental Laws (which shall for purposes of this Section 5.5 include common
law); (ii) remediation and restoration of the Assets, including, without
limitation, plugging and abandonment and remediation of Well sites; (iii) NORM;
(iv) MMMF; (v) laws relating to public or employee health and safety; and (vi)
damage to persons or property on account of Pollutants.

            Provided, however, and only to the extent the parties have not
agreed otherwise, Seller shall indemnify and save and hold harmless Buyer and
its affiliates, officers, directors, shareholders, representatives, employees,
agents, successors, and assigns from and against all Losses arising out of or
attributable to, in whole or in part, either directly or indirectly, the
condition or operation of the Assets at any time before the Closing Date that is
determined to be the result of or caused in whole or in part by Seller's
violation of, failure to fulfill duties imposed by or incurrence of liability
under, any Environmental Law. Buyer shall identify such Losses in a form similar
to that prescribed for Environmental Notices in Section 5.2.

            5.6   APPLICABILITY OF OTHER PROVISION. Section 14.5 (Reservation as
to Non-Parties) shall apply to the obligations and indemnifications provided in
this Article 5.

            5.7   BUYER'S REPORTS. Buyer shall provide to Seller, any third
party reports, or sections thereof, addressing the particular alleged
Environmental Breach, commissioned by Buyer

                                      -11-
<PAGE>

concerning an alleged Environmental Breach as set forth in a valid Environmental
Notice, such third party environmental report, or part thereof, to be included
with the Environmental Notice, subject to the parties' obligations under Section
3.2.

            5.8   EXCLUSIVE REMEDY. Notwithstanding anything else in this
Agreement to the contrary, this Article 5 is the exclusive agreement and only
remedy of Buyer in regard to Environmental Matters even if some other provision
of this Agreement by its terms would otherwise cover Environmental Matters.

            5.9   ENVIRONMENTAL DUE DILIGENCE ACTIVITIES. For the purposes of
this Agreement, Buyer has already or will, to the extent it deems appropriate,
conduct all of its environmental due diligence activities with respect to the
Assets prior to the expiration of the period during which Buyer is entitled to
give Seller Environmental Notices (such period being the "Environmental Due
Diligence Period"). Such due diligence activities shall be conducted in
accordance with and subject to the provisions of Section 3.2. During the
Environmental Due Diligence Period, Buyer agrees: (i) to keep any data or
information (including all analysis of such data) relating to Environmental
Matters acquired by Buyer strictly confidential among Buyer and Seller, (ii) to
immediately inform Seller if Buyer discovers a breach of the Environmental
Standard that would result in a material Loss, and thereafter consult with Buyer
to formulate a mutually agreeable course of action to address the Environmental
Matter, including consultations with appropriate governmental personnel.

                                    ARTICLE 6

                     SELLER'S REPRESENTATIONS AND WARRANTIES

           Seller makes the following representations and warranties:

            6.1   ORGANIZATION AND STANDING. Wasatch Oil & Gas LLC, is a limited
liability company duly organized, validly existing and in good standing under
the law of the State of Utah and is duly qualified to carry on its business in
the State of Utah. Wasatch Gas Gathering, LLC, is a limited liability company
duly organized, validly existing and in good standing under the law of the State
of Utah and is duly qualified to carry on its business in the State of Utah.
Wasatch Group, LLC, is a limited liability company duly organized, validly
existing and in good standing under the law of the State of Utah and is duly
qualified to carry on its business in the State of Utah.

            6.2   POWER. Seller has all requisite corporate power and authority
to carry on its businesses as presently conducted and to enter into this
Agreement. The execution and delivery of this Agreement and the fulfillment of
and compliance with the terms and conditions hereof will not violate, nor be in
conflict with, any material provision of Seller's organizational documents,
bylaws or any material provision of any agreement or instrument to which is a
party or by which it is bound, or, to its knowledge, any judgment, decree,
order, statute, rule or regulation applicable to it. The provisions of this
Section shall specifically include Seller's right to transfer and convey to
Buyer rights of access, rights to operate and other rights associated with the
Assets notwithstanding the pendency of the Retained Matters.

            6.3   AUTHORIZATION AND ENFORCEABILITY. The execution, delivery and
performance of this Agreement and the transactions contemplated hereby have been
duly and validly authorized

                                      -12-
<PAGE>

by all requisite action on Seller's part. This Agreement constitutes Seller's
legal, valid and binding obligation, enforceable in accordance with its terms,
subject, however, to the effects of bankruptcy, insolvency, reorganization,
moratorium and other laws for the protection of creditors, as well as to general
principles of equity, regardless whether such enforceability is considered in a
proceeding in equity or at law.

            6.4   LIABILITY FOR BROKERS' FEES. Seller has not incurred any
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.

            6.5   NO BANKRUPTCY. There are no bankruptcy proceedings pending,
being contemplated by, or to the knowledge of Seller, based upon reasonable
inquiry and investigation, threatened against Seller.

            6.6   LITIGATION. Except for matters described on Exhibit G, to the
best of Seller's knowledge, Seller has not received written notice of any
pending proceeding, "Notice of Violation," action, suit, claim or investigation
before any federal, state or other governmental court, agency or other
instrumentality involving Seller or the Assets. To the best of Seller's
knowledge there is no action, suit, proceeding, claim or investigation by any
person, entity, administrative agency or governmental body pending or threatened
against Seller before any governmental authority that impedes or is likely to
impede its ability to consummate the transactions contemplated by this
Agreement. Exhibit G sets forth Seller's description of certain matters and its
incorporation into this Agreement is not intended nor shall it be construed as
any agreement by Buyer with Seller's assessment.

            6.7   MATERIAL AGREEMENTS. To the best of Seller's knowledge,in
all material respects: (i) all Material Agreements are identified in Exhibit I;
(ii) the Material Agreements are in full force and effect and are the valid and
legally binding obligations of the parties thereto; (iii) Seller is not in
breach or default with respect to any material obligations pursuant to any
Material Agreement or any regulations incorporated therein or governing same;
(iv) all material payments (including, without limitation, royalties, delay
rentals, shut-in royalties and joint interest or other billings under unit or
operating agreements) due thereunder have been made by Seller or will be made by
Seller prior to Closing; (v) no other party of any Material Agreement (or any
successor in interest thereto) is in breach or default with respect to any of
its material obligations thereunder; and (vi) neither Seller nor any other party
to any Material Agreement has given or threatened to give notice of any action
to terminate, cancel, rescind or procure a judicial reformation of any Material
Agreement or the Leases or any provision thereof.

            6.8   TAXES. All ad valorem, property, production, severance, net
proceeds, 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 for all taxable periods prior to the taxable period in which
this Agreement is executed have been properly paid, unless contested in good
faith by appropriate proceeding. All income taxes and obligations relating
thereto that could result in a lien or other claim against any of the Assets
have been properly paid, unless contested in good faith by appropriate
proceeding.

            6.9   TAX PARTNERSHIPS. To the best of Seller's knowledge, the
Assets are not subject to any tax partnership or other agreement requiring a
partnership income tax return to be

                                      -13-
<PAGE>

filed under Subchapter K of Chapter 1 of Subtitle A of the Internal Revenue Code
of 1986, as amended (the "Code").

            6.10  LEASE MAINTENANCE. To the best of Seller's knowledge, all
material royalties (other than royalties in suspense), rentals and other
payments due under the Leases have been properly and timely paid, all conditions
necessary to keep the Leases in force have been fully performed, no notices have
been received by Seller of any claim to the contrary and all of the Leases are
in full force and effect.

            6.11  GAS IMBALANCES. To the best of Seller's knowledge, (i) Seller
is not obligated by virtue of any prepayment arrangement under any contract for
the sale of hydrocarbons containing a "take or pay" or similar provision or a
production payment or any other arrangement to deliver hydrocarbons produced
from the Assets at some future time without then or thereafter receiving full
payment therefor, (ii) Seller has not produced a share of gas greater than its
ownership percentage and Seller is under no obligation to reduce its share of
production under any gas balancing agreement or similar arrangement to allow
under-produced parties to come back into balance and (iii) as of the Effective
Time, there are no pipeline imbalances, such that the net of such imbalances is
an overdelivery or underdelivery imbalance.

            6.12  COMPLIANCE WITH LAWS, ETC. To the best of Seller's knowledge,
(i) all material valid laws, regulations and orders of all governmental agencies
having jurisdiction over the Assets have been and shall continue to be complied
with until the Closing, and (ii) all material necessary permits from and reports
to governmental agencies having jurisdiction in connection with the Assets have
been obtained and have been timely, properly and accurately made and will
continue to be timely, properly and accurately made through Closing, except as
set forth in Exhibit F.

            6.13  OTHER BURDENS. To the best of Seller's knowledge, none of the
Assets are subject to any calls on or preferential rights to market or purchase
production.

            6.14  CONDITION OF EQUIPMENT. To the best of Seller's knowledge, all
of the Wells, facilities and equipment associated with the Assets are: (a) in
good operating condition, and (b) not in need of maintenance or repairs.

            6.15  NO CHANGES. To the best of Seller's knowledge, between the
date first referenced above and Closing, there has not been, without Buyer's
prior written consent:

                  (a)   A waiver of any right relating to the Assets;

                  (b)   A sale, lease or other disposition of the Assets;

                  (c)   A mortgage, pledge or grant of a lien or security
                        interest in any of the Assets;

                  (d)   A contract for the sale of Hydrocarbons;

                  (e)   A contract between Seller and any of its affiliates; or

                  (f)   A contract or commitment to do any of the foregoing.

                                      -14-
<PAGE>

            6.16  STATEMENT OF COUNSEL. On or about February 26, 2002, counsel
for the adverse parties in the Retained Matters (described in Section 14.5) made
a written settlement offer to "sell to Wasatch, without warranty or
representation, except that Goal obtained its interest from Regoal or Ed Reott,
its judgment liens against Mission for their outstanding balance due and its
sheriff certificate and/or deed, which judgment liens have an approximate
outstanding balance of approximately $267,685.75."

                                    ARTICLE 7

                     BUYER'S REPRESENTATIONS AND WARRANTIES

            Buyer makes the following representations and warranties:

            7.1   ORGANIZATION AND STANDING. Buyer is a corporation, duly
organized, validly existing and in good standing under the law of the State of
Maryland and is duly qualified to carry on its business in the State of Utah.

            7.2   POWER. Buyer has all requisite power and authority to carry on
its business as presently conducted and to enter into this Agreement. The
execution and delivery of this Agreement and consummation of the transactions
contemplated hereby and the fulfillment of and compliance with the terms and
conditions hereof will not violate, nor be in conflict with, any material
provision of its partnership agreement or other governing documents or of any
agreement or instrument to which it is a party or by which it is bound, or, to
its knowledge, any judgment, decree, order, statute, rule or regulation
applicable to it.

            7.3   AUTHORIZATION AND ENFORCEABILITY. The execution, delivery and
performance of this Agreement have been duly and validly authorized by all
requisite corporate action on its part. This Agreement constitutes the legal,
valid and binding obligation of Buyer, enforceable in accordance with its terms,
subject, however, to the effects of bankruptcy, insolvency, reorganization,
moratorium and similar laws for the protection of creditors, as well as to
general principles of equity, regardless whether such enforceability is
considered in a proceeding in equity or at law.

            7.4   LIABILITY FOR BROKERS' FEES. Buyer has not incurred any
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.

            7.5   LITIGATION. There is no action, suit, proceeding, claim or
investigation by any person, entity, administrative agency or governmental body
pending or, to the best of Buyer's knowledge, threatened against it before any
governmental authority that impedes or is likely to impede its ability to
consummate the transactions contemplated by this Agreement and to assume the
liabilities to be assumed by it under this Agreement (except for any such
action, suit, proceeding, claim or investigation that does not and would not,
individually or in the aggregate, have a material adverse effect on the same).

            7.6   SECURITIES LAWS; SOPHISTICATION OF BUYER. The Assets are being
acquired solely for Buyer's own account for the purpose of investment and not
with a view to resale, distribution or granting a participation therein in
violation of any securities laws. Buyer is familiar

                                      -15-
<PAGE>

with the oil and gas business and it is a knowledgeable, experienced and
sophisticated investor in securities of companies engaged in the oil and gas
business. Buyer understands and accepts the risks and absence of liquidity
inherent in ownership of the Assets.

            7.7   HOLDING COMPANY. Buyer is not a "holding company," or a
"subsidiary company" of a "holding company," or an affiliate of a "holding
company" or of a "subsidiary company" of a "holding company" within the meaning
of the Public Utility Holding Company Act of 1935, as amended.

            7.8   FINANCIAL RESOURCES. Buyer has the financial resources
available to close the transaction contemplated by this Agreement without
financing that is subject to any material contingency.

            7.9   INDEPENDENT EVALUATION. Buyer is experienced and knowledgeable
in the oil and gas business and is aware of its risks. Buyer has been afforded
the opportunity to examine materials made available to it by Seller in Seller's
offices in Farmington, Utah with respect to the Assets including without
limitation the Records (collectively, the "Background Materials"). The
Background Materials are files, or copies thereof, that Seller has used in its
normal course of business and other information about the Assets that Seller has
compiled or generated. BUYER ACKNOWLEDGES AND AGREES THAT SELLER HAS MADE NO
REPRESENTATIONS OR WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, WRITTEN OR ORAL,
AS TO THE ACCURACY OF THE BACKGROUND MATERIALS OR ANY OTHER INFORMATION RELATING
TO THE ASSETS FURNISHED BY OR ON BEHALF OF SELLER OR TO BE FURNISHED TO BUYER OR
ITS REPRESENTATIVES, INCLUDING WITHOUT LIMITATION ANY INTERNAL APPRAISALS AND/OR
INTERPRETIVE DATA OF SELLER OR OF THE RIGHT OF ANY PERSON OR ENTITY TO RELY
THEREON. Buyer acknowledges and affirms that it has relied and will rely solely
upon its independent analysis, evaluation and investigation of, and judgment
with respect to, the business, economic, legal, tax or other consequences of
this transaction including its own estimate and appraisal of the extent and
value of the petroleum, natural gas and other reserves of the Assets. To the
extent Buyer deemed appropriate, Buyer's representatives visited Seller's
offices and have been given sufficient opportunities to examine the books and
records of Seller relating to the Assets. Neither Seller nor its affiliates,
agents, representatives or employees shall have any liability to Buyer or its
agents, representatives or employees resulting from any use, authorized or
unauthorized, of the Background Materials or other information relating to the
Assets provided by or on behalf of Seller or its agents, representatives or
employees. Provided, however, that the foregoing shall not apply to any analysis
made by Buyer or obligations of Seller in connection with the matters addressed
in Article 6 and Article 14.

                                    ARTICLE 8

                            COVENANTS AND AGREEMENTS

            8.1   COVENANTS AND AGREEMENTS OF SELLER. Seller covenants and
agrees with Buyer as follows:

                  (a)   Operations Prior to Closing. Except as otherwise
consented to in writing by Buyer or provided in this Agreement from the date of
execution hereof to the Closing,

                                      -16-
<PAGE>

Seller shall use reasonable efforts to maintain and operate the properties in a
good and workmanlike manner consistent with past practices, but with no
obligation to improve the same from and after the date hereof. Subject to the
provisions of Section 2.4, Seller shall pay or cause to be paid its
proportionate share of all costs and expenses incurred in connection with such
operations. To the extent Seller receives written AFEs or actual notice of such,
Seller shall notify Buyer of ongoing activities and major capital expenditures
in excess of $10,000 per activity net to Seller's interest conducted on the
Assets and shall consult with Buyer regarding all such matters and operations.

                  (b)   Restriction on Operations. Subject to Section 8.1(a),
unless Seller obtains the prior written consent of Buyer to act otherwise
(which, will not be unreasonably withheld, delayed or conditioned), prior to
Closing Seller will use good faith efforts within the constraints of the
applicable operating agreements and other applicable agreements to not (i)
abandon any part of the Assets (except in the ordinary course of business or the
abandonment of leases upon the expiration of their respective primary terms or
if not capable of production in paying quantities), (ii) approve any operations
on the properties anticipated in any instance to cost the owner of the Assets
more than $10,000 per activity net to Seller's interest (excepting emergency
operations, operations required under presently existing contractual
obligations, ongoing commitments under existing AFEs and operations undertaken
to avoid a monetary penalty or forfeiture provision of any applicable agreement
or order), (iii) convey or dispose of any material part of the Assets (other
than replacement of equipment or sale of oil, gas, and other liquid products
produced from the Assets in the regular course of business) or enter into any
farmout, farmin or other similar contract affecting the Assets if the net
expense to Seller's interest will be in excess of $10,000, (iv) let lapse any
insurance now in force with respect to the Assets, or (vi) materially modify or
terminate any of the Material Agreements.

                  (c)   Marketing. Unless Seller obtains the prior written
consent of Buyer to act otherwise, prior to Closing Seller will not alter any
existing marketing contracts currently in existence, or enter into any new
marketing contracts or agreements providing for the sale of Hydrocarbons for a
term in excess of 30 days.

                  (d)   Consents. For the purposes of obtaining the written
consents required in this Section 8.1, this Section 8.1(d) shall control over
Section 15.3, and Buyer designates the following contact person:

                                      -17-
<PAGE>

                         Buyer:     Bill Barrett Corporation
                                    1099 18th Street, Suite 2300
                                    Denver, Colorado  80202
                         Attn:      Hunt Walker
                         Telephone: (303) 293-9100
                         Fax:       (303) 291-0420

Such consents may be obtained in writing or fax, or given verbally if confirmed
by writing.

                  (e)   Status. Seller shall maintain its respective
organizational status from the date hereof until the resolution of the Retained
Matters (as defined in Section 14.5) and to assure that as of the Closing Date
it will not be under any material restriction that would prohibit or delay the
timely consummation of the transactions contemplated hereby.

                  (f)   Notices of Claims. Seller shall promptly notify Buyer,
if, prior to the Closing Date, Seller receives written notice of any claim,
suit, action or other proceeding of the type contemplated in Section 6.6.

                  (g)   Compliance with Laws. Prior to the Closing Date, Seller
shall attempt in good faith to comply in all material respects with all
applicable statutes, ordinances, rules, regulations and orders relating to the
ownership and operation of the Assets.

                  (h)   Insurance. Prior to the Closing Date, Seller shall
maintain its insurance as such insurance is now in force with respect to the
Assets.

                  (i)   Resolution of Retained Matters. Seller shall use its
best efforts to attempt to resolve the Retained Matters (as defined in Section
14.5) prior to Closing.

            8.2   COVENANTS AND AGREEMENTS OF BUYER. Buyer covenants and agrees
with Seller that:

                  (a)   Status. Buyer shall maintain its legal status from the
date hereof until resolution of the Retained Matters (as defined in Section 14.5
below) . As of the Closing Date, Buyer will not be under any material
restriction that would prohibit or delay the timely consummation of the
transactions contemplated hereby.

                  (b)   Bonding; Insurance. On or before five (5) days prior to
Closing, Buyer shall provide evidence to Seller that Buyer has arranged to have
in place, to be effective at Closing and relating to the ownership of the Assets
after the Closing (i) all necessary state, federal and local bonds, and (ii)
upon Seller's request, insurance as is reasonable and customary in the industry
for properties comparable to the Assets.

            8.3   COVENANTS AND AGREEMENTS OF THE PARTIES.

                  (a)   Government Reviews and Filings. Before and after the
Closing, Seller and Buyer shall cooperate to provide requested information, make
required filings with, prepare applications to and conduct negotiations with
each governmental agency as required to consummate the transaction contemplated
hereby. Each party shall make any governmental filings occasioned by

                                      -18-
<PAGE>

its ownership or structure. Buyer shall make all filings after the Closing at
its expense with governmental agencies necessary to transfer title to the Assets
or to comply with laws and shall indemnify and hold harmless Seller from and
against all claims, costs, expenses, liabilities and actions arising out of
Seller's holding of such title after the Closing and prior to the securing of
any necessary governmental approvals of the transfer.

                  (b)   Data and Information.

                        (1)   Confidentiality. All data and information obtained
from Seller in connection with the transactions contemplated by this Agreement
whether before or after the execution of this Agreement, and data and
information generated by Buyer in connection with this transaction (collectively
the "Information") is deemed by the parties to be confidential and proprietary
to Seller. Until completion of the Closing (and for a period of two (2) years if
Closing should not occur for any reason), except as required by law, Buyer and
its officers, agents and representatives will hold in strict confidence the
terms of this Agreement and all Information, except any Information which: (i)
at the time of disclosure to Buyer by Seller is in the public domain; (ii) after
disclosure to Buyer by Seller becomes part of the public domain by publication
or otherwise, except by breach of this covenant by Buyer; (iii) Buyer can
establish by competent proof was rightfully in its possession at the time of
disclosure to Buyer by Seller; (iv) Buyer rightfully receives from third parties
free of any obligation of confidence; (v) is disclosed to Buyer's consultants,
investors and lenders who similarly agree to protect the confidentiality of such
Information and agree to use such Information only for their due diligence
evaluation of the Assets; or (vi) is developed independently by Buyer, provided
that the person or persons developing the Information shall not have had access
to the Information.

                        (2)   Return of Information. If the transaction
contemplated by this Agreement does not close on or before the Closing Date,
Buyer shall (i) return to Seller all copies of the Information generated by
Seller or otherwise in the possession of Buyer obtained under the terms of this
Agreement, which Information is at the time of termination required to be held
in confidence pursuant to Section 8.3(b)(1); (ii) not utilize or permit
utilization of the Information to compete with Seller; and (iii) destroy any and
all notes, reports, studies or analyses made or generated by Buyer, based on or
incorporating the Information. The terms of this Section 8.3(b) shall survive
termination of this Agreement.

                        (3)   Buyer agrees that Seller will not have an adequate
remedy at law if Buyer violates any of the terms of this Section 8.3(b). In such
event, Seller will have the right, in addition to any other right it may have,
to obtain injunctive relief to restrain any breach or threatened breach of the
terms of this Section 8.3(b) or to obtain specific enforcement of such terms.

                  (c)   Lavinia Well. If Wasatch acquires the Lavinia 1-32 Well
(the "Lavinia Well") from Reott/Goal, within a period of one year after the
Effective Time, Buyer will gather and transport Seller's share of gas from the
Lavinia Well for a fee comparable to the fee charged other producers on the Gas
Gathering System. Further Buyer's pumper will perform the same services for the
Lavinia Well at rates comparable to the rates charged for similar services on
other wells in the field.

                                      -19-
<PAGE>

                                    ARTICLE 9

                                   TAX MATTERS

            9.1   APPORTIONMENT OF TAX LIABILITY. "Taxes" shall mean all ad
valorem, property, production, excise, conservation, net proceeds, severance,
and all other taxes and similar obligations assessed against the Assets or based
upon or measured by the ownership of the Assets or the production of
Hydrocarbons or the receipt of proceeds therefrom, other than income taxes. With
respect to the Assets and all personal property associated therewith, all Taxes
shall be prorated between Seller and Buyer as of the Effective Time for all
taxable periods that include the Effective Time based upon the date such Taxes
are assessed.

            9.2   CALCULATION OF TAX LIABILITY. Consistent with Section 9.1 and
with respect to the tax liability apportioned in Section 9.1, if any Taxes are
incurred by Seller for a tax period which commences prior to the Effective Time
and extends for a period after the Effective Time, then the respective parties'
liability, if any, for such Taxes for both the period prior to the Effective
Time and the period subsequent to the Effective Time shall be determined by
prorating such Taxes to Seller in the ratio that the number of days in the
assessment period, as appropriate, before the Effective Time bears to the total
number of days in the assessment period, and to the Buyer in the ratio that the
number of days in the assessment period on or after the Effective Time bears to
the total number of days in the assessment period. Based on the best current
information available as of Closing, the proration shall be made between the
parties as an adjustment to the Purchase Price in accordance with Section 2.4.
Taxes for the Tax Year 2002 will be due and payable by Buyer on or about
November 30, 2002, and will include the portion of such 2002 Tax Year during
which Seller owned the Assets (i.e., January 1, 2002 through March 31, 2002).
Therefore, Seller shall provide an estimate of the 2002 taxes no later than five
(5) days prior to the Closing Date, with reasonable and adequate calculations
indicating the basis for such estimate. The parties shall agree to such estimate
as a condition of Closing. Buyer shall receive a downward adjustment to the
Purchase Price for such estimated amount of Taxes for January 1, 2002 through
March 31, 2002. Said estimated amount shall be included in the Preliminary
Settlement Statement. Buyer shall not be required to refund any amount to
Seller, and Seller shall not be required to pay any additional amount to Buyer
in the event the actual 2002 ad valorem taxes are less or greater than such
estimate.

            9.3   TAX REPORTS AND RETURNS. For the tax period in which the
Effective Time occurs, Seller agrees to immediately forward to Buyer any such
tax reports and returns received by Seller after Closing and provide Buyer with
appropriate information which is necessary for Buyer to file any required tax
reports and returns. Buyer agrees to file all tax returns and reports applicable
to the Assets that Buyer is required to file after the Closing, and pay all
required Taxes payable with respect to the Assets subject to the provisions of
Section 9.1.

            9.4   SALES AND TRANSFER TAXES. Buyer shall be liable for and shall
indemnify Seller for, any sales and use taxes, conveyance, transfer, and real
estate transfer stamps or taxes that may be imposed on any transfer of the
Assets pursuant to this Agreement. If required by applicable law, Buyer shall,
in accordance with applicable law, calculate and remit any sales or similar
taxes that are required to be paid as a result of the transfer of the Assets to
Buyer. If Seller receives notice that any sales and/or use taxes are due, Seller
shall promptly forward such notice to Buyer for handling.

                                      -20-
<PAGE>

                                   ARTICLE 10

                              CONDITIONS TO CLOSING

            10.1  SELLER'S CONDITIONS. The obligations of Seller at the Closing
are subject, at the option of Seller, to the satisfaction at or prior to the
Closing of the following conditions precedent:

                  (a)   All Buyer's representations and warranties contained in
Article 7 of this Agreement shall be true in all material respects at and as of
the Closing in accordance with their terms as if such representations and
warranties were remade at and as of the Closing, and Buyer shall have performed
and satisfied all covenants and agreements required by this Agreement to be
performed and satisfied by Buyer at or prior to the Closing in all material
respects;

                  (b)   No order shall have been entered by any court or
governmental agency having jurisdiction over the parties or the subject matter
of this Agreement that restrains or prohibits the purchase and sale contemplated
by this Agreement and which remains in effect at the time of Closing; and

                  (c)   Seller shall have received the evidence of bonding and
insurance as required in Section 8.2(b).

                  (d)   The Total of all Defect Adjustments and Exclusion
Adjustments shall not exceed ten percent (10%) of the Purchase Price.

            10.2  BUYER'S CONDITIONS. The obligations of Buyer at the Closing
are subject, at the option of Buyer, to the satisfaction at or prior to the
Closing of the following conditions:

                  (a)   All representations and warranties of Seller contained
in Article 6 of this Agreement shall be true in all material respects at and as
of the Closing in accordance with their terms as if such representations and
warranties were remade at and as of the Closing and Seller shall have performed
and satisfied all covenants and agreements required by this Agreement to be
performed and satisfied by Seller at or prior to the Closing in all material
respects;

                  (b)   No order shall have been entered by any court or
governmental agency having jurisdiction over the parties or the subject matter
of this Agreement that restrains or prohibits the purchase and sale contemplated
by this Agreement and which remains in effect at the time of Closing; and

                  (c)   The Total of all Defect Adjustments and Exclusion
Adjustments, as well as any other downward adjustments under this Agreement
(including, without limitation, for any Net Casualty Loss) shall not exceed ten
percent (10%) of the Purchase Price.

                  (d)   No later than ten (10) days before Closing, Buyer shall
have received adequate financial information regarding Wasatch Group, LLC,
including but not limited to audited financial statements for calendar year
2001, financial statements for the first quarter of calendar year 2002, and such
other supporting documentation as Buyer may request. All such financial
information delivered to Buyer shall be maintained as confidential.

                                      -21-
<PAGE>

                                   ARTICLE 11

                      RIGHT OF TERMINATION AND ABANDONMENT

            11.1  TERMINATION . This Agreement may be terminated in accordance
with the following provisions:

                  (a)   by Seller, prior to Closing, if the conditions set forth
in Section 10.1 are not satisfied through no fault of Seller, or waived by
Seller as of the Closing Date;

                  (b)   by Buyer, prior to Closing, if the conditions set forth
in Section 10.2 are not satisfied through no fault of Buyer or waived by Buyer
as of the Closing Date; or

                  (c)   by Seller or Buyer, prior to Closing, if, through no
fault of the other party, the Closing does not occur on or before the date
specified in Section 12.1.

            11.2  LIABILITIES UPON TERMINATION OR BREACH .

                  (a)   Buyer's Breach. If the transactions contemplated by this
Agreement are not consummated on or before the date specified in Section 12.1 by
reason of Buyer's failure to tender performance at Closing and Seller is in
compliance with the terms of this Agreement and terminates this Agreement, or if
Seller terminates this Agreement pursuant to Section 11.1(a), Seller shall
retain the Deposit as liquidated damages and Seller shall have no further
obligation to Buyer with respect to the Assets or under this Agreement. The
remedy set forth herein shall be Seller's sole and exclusive remedy for Buyer's
wrongful failure to close hereunder and Seller expressly waives any and all
other remedies, legal and equitable, that it otherwise may have for Buyer's
failure to close.

                  (b)   Seller's Breach. If the transactions contemplated by
this Agreement are not consummated on or before the date specified in Section
12.1 by reason of Seller's failure to tender performance at Closing and Buyer is
in compliance with the terms of this Agreement and terminates this Agreement,
then Buyer shall have the right to demand Seller's specific performance of the
transactions contemplated by this Agreement.

                  (c)   Termination Without Further Liability. If this Agreement
is terminated by the mutual agreement of the parties, if this Agreement is
terminated because the conditions set forth in Section 10.1(d) or 11.1(c) are
not met, or if this Agreement is terminated pursuant to Section 11.1(b), and
Buyer does elect to pursue the remedy set forth in Section 11.2(b), Seller shall
return the Deposit to Buyer, and each party shall release the other party for
any and all liabilities and obligations under the terms of this Agreement.

                                      -22-
<PAGE>

                                   ARTICLE 12

                                     CLOSING

            12.1  DATE OF CLOSING. Unless otherwise agreed to in writing and
subject to the conditions stated in this Agreement, consummation of the
transactions contemplated hereby (the "Closing") shall be held on or before
April 30, 2002. The date the Closing actually occurs is called the "Closing
Date."

            12.2  PLACE OF CLOSING. The Closing shall be held at the offices of
Patton Boggs, 1660 Lincoln Street, Suite 1900, Denver, Colorado, at 9:00 a.m.
Mountain Standard Time or at such other time and place as Buyer and Seller may
agree in writing.

            12.3  CLOSING OBLIGATIONS. 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:

                  (a)   Seller shall execute, acknowledge and deliver to Buyer
(1) an Assignment, Bill of Sale and Conveyance of the Assets, effective as of
the Effective Time to Buyer (in sufficient counterparts to facilitate filing and
recording) substantially in the form of Exhibit D conveying the Assets with a
special warranty of title, but with no other warranties, express or implied, and
in their existing condition "as is, where is"; and (2) such other assignments,
bills of sale, or deeds necessary to transfer the Assets to Buyer, including
without limitation any conveyances on official forms and related documentation
necessary to transfer the Assets to Buyer in accordance with requirements of
governmental regulations (collectively, the "Conveyances");

                  (b)   Seller and Buyer shall execute and deliver the
Preliminary Settlement Statement;

                  (c)   Buyer shall deliver to Seller the Closing Amount by wire
transfer in immediately available funds, or by such other method as may be
agreed to by the parties hereto;

                  (d)   Seller shall deliver to Buyer possession of the Assets;

                  (e)   Seller and Buyer shall execute and deliver letters in
lieu directing all purchasers of production to pay Buyer the proceeds
attributable to production from the Assets from and after the Effective Time;

                  (f)   Buyer shall deliver to Seller evidence of appropriate
federal, state and local bonds relating to ownership of the Assets after the
Closing and certificates of insurance evidencing that Buyer has obtained
appropriate insurance covering the Assets;

                  (g)   Seller shall deliver to Buyer a certificate
substantiating its non-foreign status in accordance with Treasury Regulations
under Section 1445 of the Code, in the form of Exhibit E ("FIRPTA Certificate");
and

                  (h)   Buyer shall prepare and Seller shall execute and deliver
to Buyer all forms reasonably necessary for Buyer to assume operations on the
Assets as agreed to by the parties.

                                      -23-
<PAGE>

                                   ARTICLE 13

                            POST-CLOSING OBLIGATIONS

            13.1  POST-CLOSING ADJUSTMENTS.

                  (a)   As soon as practicable after the Closing, but in no
event later than ninety (90) days after Closing, Seller shall prepare and
deliver to Buyer, in accordance with GAAP, a final settlement statement (the
"Final Settlement Statement") setting forth each adjustment or payment that was
not finally determined as of the Closing and showing the calculation of such
adjustment and the resulting final purchase price (the "Final Purchase Price").
As soon as practicable after receipt of the Final Settlement Statement, but in
no event later than on or before thirty (30) days after receipt of Seller's
proposed Final Settlement Statement, Buyer shall deliver to Seller a written
report containing any changes that Buyer proposes to make to the Final
Settlement Statement. Buyer's failure to deliver to Seller a written report
detailing proposed changes to the Final Settlement Statement by that date shall
be deemed an acceptance by Buyer of the Final Settlement Statement as submitted
by Seller. The parties shall agree with respect to the changes proposed by
Buyer, if any, no later than fifteen (15) days after receipt by Seller of
Buyer's comments to the Final Settlement Statement. The date upon which such
agreement is reached or upon which the Final Purchase Price is established for a
transaction shall be herein called the "Final Settlement Date." If (1) the Final
Purchase Price is more than the Closing Amount, Buyer shall pay Seller the
amount of such difference, or (2) the Final Purchase Price applicable to Buyer
is less than the Closing Amount, Seller shall pay to Buyer the amount of such
difference, in either event by wire transfer of immediately available funds.
Payment by Buyer or Seller, as the case may be, shall be within five (5) days of
the Final Settlement Date. The Final Settlement Statement and the Final Purchase
Price paid thereunder shall be a final settlement as between Buyer and Seller
for all adjustments to the Purchase Price.

                  (b)   If Seller does not elect to cure or is unable to cure
such Title Defects to the reasonable satisfaction of Buyer within forty-five
(45) days after Closing, Buyer shall have the option to either accept assignment
of the Asset affected by any such Title Defect, and the Purchase Price shall be
adjusted downward by the Actual Defect Value ("TITLE DEFECT ADJUSTMENT"), as
applicable, or to exclude such Asset from this Agreement (collectively, the
"EXCLUDED ASSETS"). If Buyer elects to exclude such Assets, the Purchase Price
shall be adjusted downward by an amount equal to the Allocated Value of the
Excluded Assets, and reflected in the Final Settlement Statement, and Buyer
shall reassign such Excluded Assets.

            13.2  RECORDS. Within two (2) business days following the Closing
Date, Seller shall make the Records available for pick up by Buyer. Seller may
retain copies of the Records and Seller and Seller's predecessors in title shall
have the right to review and copy the Records during business hours upon
reasonable notice to Buyer. Buyer agrees to not destroy or otherwise dispose of
the Records for a period of 6 years after the Closing without giving Seller
reasonable notice and an opportunity to copy such Records.

            13.3  TRANSFER AND RECORDING FEES. Buyer shall pay all documentary,
transfer, filing, licensing, and recording fees required in connection with the
processing, filing, licensing or recording of any assignments, titles or bills
of sale.

                                      -24-
<PAGE>

            13.4  ADDITIONAL PROCEEDS AND INVOICES. From and after the Closing,
promptly after its receipt thereof, but only to the extent that such proceeds or
invoices shall not have been the subject of an adjustment to the Purchase Price,
(i) Seller agrees to pay promptly to Buyer any and all proceeds received by
Seller that are attributable to the post-Effective Time production of
Hydrocarbons from the Assets and to forward all unpaid invoices received by
Seller that are attributable to the production of Hydrocarbons from the Assets
on or after the Effective Time and (ii) Buyer agrees to pay promptly to Seller
any and all proceeds that are attributable to the pre-Effective Time production
of Hydrocarbons from the Assets and to forward all unpaid invoices received by
Buyer that are attributable to the production of Hydrocarbons from the Assets
prior to the Effective Time, including any of such proceeds that were held in
suspense by the purchasers of production.

            13.5  FURTHER ASSURANCES. From time to time after Closing, Seller
and Buyer shall each execute, acknowledge and deliver to the other such further
instruments and take such other action as may be reasonably requested in order
more effectively to assure to the other the full beneficial use and enjoyment of
the Assets and otherwise to accomplish the purposes of the transactions
contemplated by this Agreement.

            13.6  SUSPENSE FUNDS. With the exception of funds held under legal
suspense, Seller agrees to convey and Buyer agrees to receive all suspense funds
held by Seller, as of the date Buyer assumes the accounting functions relating
to the Assets, for the benefit of royalty, overriding royalty interest (and all
other such non-cost bearing interests) and working interest owners attributable
to the Assets, and Buyer shall assume and defend, indemnify and hold Seller and
its employees harmless from all costs, expenses, claims, demands and causes of
action associated with such funds, but only as to the suspense funds actually
transferred and not as to any liability resulting from Seller's failure to pay
or retain any amounts prior to the Closing Date.

                                   ARTICLE 14

                            ASSUMPTION OF OBLIGATIONS
                               AND INDEMNIFICATION

            14.1  ASSUMPTION OF LIABILITIES AND OBLIGATIONS BY BUYER. UPON
CLOSING, BUYER SHALL ASSUME AND PAY, PERFORM, FULFILL AND DISCHARGE ALL CLAIMS,
COSTS, EXPENSES, LIABILITIES AND OBLIGATIONS ACCRUING OR RELATING TO (i) THE
OWNING, DEVELOPING, EXPLORING, 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 TIME, INCLUDING WITHOUT LIMITATION, THE
PAYMENT OF CAPITAL/LOE/JIB EXPENSES AND TAXES, THE OBLIGATIONS TO PLUG AND
ABANDON ALL WELLS AND RECLAIM ALL WELL SITES, THE MAKE-UP AND BALANCING
OBLIGATIONS FOR OVERPRODUCTION OF GAS FROM THE WELLS, ALL OBLIGATIONS ARISING
UNDER THE MATERIAL AGREEMENTS, AND (II) THE FAILURE OF ANY OF BUYER'S WARRANTIES
AND REPRESENTATIONS HEREUNDER TO BE TRUE (COLLECTIVELY, THE "ASSUMED
LIABILITIES").

            14.2  BUYER'S INDEMNIFICATION OF SELLER. AFTER THE CLOSING, BUYER
SHALL ASSUME ALL RISK, LIABILITY, OBLIGATION AND LOSSES IN CONNECTION WITH, AND
SHALL DEFEND, INDEMNIFY AND SAVE AND HOLD HARMLESS SELLER, ITS OFFICERS,
DIRECTORS, SHAREHOLDERS, EMPLOYEES, REPRESENTATIVES, AGENTS, BENEFICIARIES,
PERSONAL REPRESENTATIVES, SUCCESSORS AND ASSIGNS FOREVER FROM AND AGAINST

                                      -25-
<PAGE>

ALL LOSSES (OTHER THAN LOSSES ARISING FROM SELLER'S (a) RETAINED LIABILITIES,
AND (b) LIABILITIES FOR ENVIRONMENTAL MATTERS UNDER ARTICLE 5) WHICH ARISE FROM
OR IN CONNECTION WITH (i) THE ASSUMED LIABILITIES, (II) ANY MATTER FOR WHICH
BUYER HAS AGREED TO INDEMNIFY SELLER IN THIS AGREEMENT, OR (III) ANY BREACH BY
BUYER OF THIS AGREEMENT (SUBJECT TO THE LIMITATIONS OF SECTION 11.2). "LOSSES"
SHALL MEAN ANY ACTUAL LOSS, COST, EXPENSE, LIABILITY (INCLUDING, CIVIL FINES),
DAMAGE, DEMANDS, SUITS, SANCTIONS OF EVERY KIND AND CHARACTER INCLUDING
REASONABLE FEES AND EXPENSES OF ATTORNEYS, TECHNICAL EXPERTS AND EXPERT
WITNESSES REASONABLY INCIDENT TO MATTERS INDEMNIFIED AGAINST. BUYER SHALL BE
DEEMED TO HAVE RELEASED SELLER AT THE CLOSING FROM ANY LOSSES FOR WHICH BUYER
HAS AGREED TO INDEMNIFY SELLER HEREUNDER.

            14.3  LIABILITIES AND OBLIGATIONS RETAINED BY SELLER. SUBJECT TO
SECTION 13.1, SELLER HEREBY RETAINS AND SHALL PAY, PERFORM, FULFILL AND
DISCHARGE ALL CLAIMS, COSTS, EXPENSES, LIABILITIES AND OBLIGATIONS ACCRUING OR
RELATING TO (i) THE OWNING, DEVELOPING, EXPLORING, OPERATING OR MAINTAINING OF
THE ASSETS OR THE PRODUCING, TRANSPORTING AND MARKETING OF HYDROCARBONS FROM THE
ASSETS, RELATING TO PERIODS BEFORE THE EFFECTIVE TIME, INCLUDING WITHOUT
LIMITATION, THE PAYMENT OF CAPITAL/LOE/JIB EXPENSES AND TAXES AND ALL
OBLIGATIONS ARISING UNDER THE MATERIAL AGREEMENTS, AND (II) THE FAILURE OF ANY
OF SELLER'S WARRANTIES AND REPRESENTATIONS HEREUNDER TO BE TRUE (COLLECTIVELY,
THE "RETAINED LIABILITIES").

            14.4  SELLER'S INDEMNIFICATION OF BUYER. AFTER THE CLOSING, SELLER
SHALL DEFEND, INDEMNIFY AND SAVE AND HOLD HARMLESS BUYER, ITS PARTNERS,
EMPLOYEES, REPRESENTATIVES, AGENTS, BENEFICIARIES, PERSONAL REPRESENTATIVES,
SUCCESSORS AND ASSIGNS FOREVER FROM AND AGAINST ALL LOSSES (OTHER THAN LOSSES
ARISING FROM BUYER'S ASSUMED LIABILITIES) WHICH ARISE FROM OR IN CONNECTION WITH
(i) THE RETAINED LIABILITIES, (II) ANY MATTER FOR WHICH SELLER HAS AGREED TO
INDEMNIFY BUYER IN THIS AGREEMENT, OR (III) ANY BREACH BY SELLER OF THIS
AGREEMENT (SUBJECT TO THE LIMITATIONS OF SECTION 11.2). "LOSSES" SHALL HAVE THE
MEANING SET FORTH IN SECTION 14.2. SELLER SHALL BE DEEMED TO HAVE RELEASED BUYER
AT THE CLOSING FROM ANY LOSSES FOR WHICH SELLER HAS AGREED TO INDEMNIFY BUYER
HEREUNDER.

            14.5  SELLER'S ADDITIONAL OBLIGATIONS RELATING TO THE RETAINED
MATTERS.

                  (a)   Seller's Retention of Obligations. Notwithstanding
anything to the contrary in this Agreement, Seller shall retain all risk,
liability and obligation associated with the matters described in Exhibit G,
including but not limited to those matters encompassed in or relating to the Key
Energy Judgment, the J-West Judgment, the Reott Judgment, the Quiet Title
Action, the Redeemed Properties, the Motion Properties (as those terms are
defined in Exhibit G), the Sheriff's Deed dated March 6, 2002 (attached as
Exhibit J) or any other claims raised by Key Energy, J-West or Reott
(collectively "the Retained Matters"). Exhibit G sets forth Seller's description
of certain portions of the Retained Matters and its incorporation into this
Agreement is not intended nor shall it be construed as any agreement by Buyer
that Exhibit G is a complete description of all the claims or potential claims
or that Seller's assessment of the validity of the claims at issue.

                  (b)   Seller's Indemnification of Buyer. Notwithstanding
anything to the contrary in this Agreement, Seller shall indemnify, hold
harmless and defend Buyer, its successors, and assigns (collectively, "Buyer")
from and against all claims, liability, liens, loss and damage (collectively,
"Claims") arising out of or directly or indirectly in connection with the
Retained Matters, and including without limitation, any costs, expenses and
attorneys fees arising out of or caused by such Claims whether or not resulting
or alleged to result from the negligence, including

                                      -26-
<PAGE>

sole negligence, or fault of Buyer. Buyer shall also have the right, upon notice
to Seller, to assume control of its own defense or other legal representation in
connection with any Claim against Buyer and Seller shall reimburse Buyer for all
reasonable related costs, expenses and attorneys fees.

                  Claims, within the scope of this Section 14.5, shall
specifically include losses incurred by Buyer if the transfer of any portion of
the Assets to Buyer is invalidated after Closing, which shall specifically
include any increase in the value of the Assets between the Effective Time and
the effective date of Buyer's loss of title to the Asset(s) or any portion
thereof, as well as any capital improvements, investments or other expenditures
made by Buyer in connection with its use of the affected Asset(s).

                  (c)   Settlement of Claims. Seller shall not enter into any
settlement or other voluntary resolution of Claims within the scope of this
Section 14.5 without the prior written approval of Buyer, which shall not be
unreasonably withheld.

                  (d)   Escrow Account. Seller shall deposit the amount of Two
Hundred Sixty-Seven Thousand Six Hundred Eighty-Five Dollars and Seventy-Five
Cents ($267,685.75) into an escrow account (the "Escrow Account"), which shall
be maintained until resolution and termination of the Retained Matters and
governed by the Escrow Agreement attached as Exhibit K. The initial amount of
the Escrow Account is based upon: (i) Seller's representation set forth in
Section 6.16 and (ii) the assumption of obligations set forth in Section 14.7
and the financial information provided to Buyer, pursuant to Section 10.2(d), by
Wasatch Group, LLC.

The Escrow Account will be held by Patton Boggs and interest on the funds in the
Escrow Account will be the property of the party to whom the funds are
ultimately released. Funds in the Escrow Account shall be utilized to pay for
the following: (i) any approved settlements reached or final judgments entered
in the Retained Matters; (ii) defense or other legal costs of Buyer if Seller
fails to reimburse Buyer for costs incurred within 30 days; (iii)
indemnification of Buyer for Claims if Seller. Provided, however, that if Buyer
utilizes funds in the Escrow Account for payment of defense or other legal
costs, then Seller shall be obligated to deposit additional funds into the
account within 15 days or Seller shall be in material breach of this Agreement.
Provided, further, that if Buyer determines, in its reasonable discretion, that
the potential cost of Claims associated with the Retained Matters will exceed
$267,685.75, then Buyer shall notify Seller and Seller shall contribute such
additional funding as Buyer may required to the Escrow Account within 30 days of
such notice.

                  (e)   No Limitations. Notwithstanding anything to the contrary
in this Agreement, Seller's obligations under this Article 14.5 shall not be
subject to any limitations as to types of damages or other limitations of
liability, including but not limited to those set forth in Articles 2, 4, 13 and
other portions of this Article 14.

                  (f)   Release of Buyer. Seller hereby releases Buyer from and
shall indemnify Buyer for any obligation to reimburse or refund income or other
benefit derived by Buyer from any Assets affected by the Retained Matters if the
transfer of such Assets to Buyer is declared void or otherwise ineffective.

                  (g)   Survival The obligations set forth in this Article 14.5
shall survive Closing and/or the termination of this Agreement.

                                      -27-
<PAGE>

            14.6  RESERVATION AS TO NON-PARTIES. Nothing herein is intended to
limit or otherwise waive any recourse Buyer (or Seller) may have against any
non-party for any obligations or liabilities which may be incurred with respect
to the Assets.

            14.7  PARENT GUARANTEE; JOINT AND SEVERAL LIABILITY. By its
execution of this Agreement, Wasatch Group, LLC, the parent corporation of both
Wasatch Oil & Gas, LLC, and Wasatch Gas Gathering, LLC, fully guarantees the
performance of both Wasatch Oil & Gas, LLC, and Wasatch Gas Gathering, LLC,
wholly-owned subsidiaries of Wasatch Group, LLC, pursuant to the terms and
conditions of this Agreement.

                                   ARTICLE 15

                                  MISCELLANEOUS

            15.1  EXHIBITS. The Exhibits referred to in this Agreement are
hereby incorporated in this Agreement by reference and constitute a part of this
Agreement.

            15.2  EXPENSES. Except as otherwise specifically provided, all fees,
costs and expenses incurred by Buyer or Seller in negotiating this Agreement or
in consummating the transactions contemplated by this Agreement shall be paid by
the party incurring the same, including, without limitation, legal and
accounting fees, costs and expenses.

            15.3  NOTICES. Except as provided in Section 8.1(d), all notices and
communications required or permitted 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, when received, (ii) if sent by certified mail, return
receipt requested, three (3) days after sending, or (iii) if sent by overnight
courier, one day after sending. All notices shall be addressed as follows:

                        IF TO SELLER:

                             Wasatch Oil & Gas
                             P.O. Box 699
                             Farmington, Utah  84025-0699
                             Attn: Todd D. Cusick
                             Telephone:  (801) 451-9200
                             Fax:  (801) 451-9204

                        IF TO BUYER:

                             Bill Barrett Corporation
                             1099 18th Street, Suite 2300
                             Denver, Colorado  80202
                             Attn:  Hunt Walker
                             Telephone: (303) 293-9100
                             Fax:  (303) 291-0420

                                      -28-
<PAGE>

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

            15.4  AMENDMENTS. Except for waivers specifically provided for in
this Agreement, this Agreement may not be amended nor any rights hereunder
waived except by an instrument in writing signed by the party to be charged with
such amendment or waiver and delivered by such party to the party claiming the
benefit of such amendment or waiver.

            15.5  ASSIGNMENT. Buyer shall not assign all or any portion of its
respective rights or delegate all or any portion of its respective duties
hereunder unless with Seller's advance written consent and except if Buyer
continues to remain liable for the performance of its obligations hereunder;
provided that Buyer may not assign the benefits of Seller's indemnity given
pursuant to Article 5 and any permitted assignment shall not include such
benefits. No such assignment or obligation shall increase the burden on Seller
or impose any duty on Seller to communicate with or report to any transferee,
and Seller may continue to look to Buyer for all purposes under this Agreement.

            15.6  ANNOUNCEMENTS. Seller and Buyer shall consult with each other
with regard to all press releases and other announcements issued after the date
of this Agreement and prior to the Closing Date 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
publicity without the prior written consent of the other party, which consent
shall not be unreasonably withheld.

            15.7  HEADINGS. The headings of the Articles and Sections of this
Agreement are for guidance and convenience of reference only and shall not limit
or otherwise affect any of the terms or provisions of this Agreement.

            15.8  COUNTERPARTS. This Agreement may be executed by Buyer and
Seller in any number of counterparts, each of which shall be deemed an original
instrument, but all of which together shall constitute but one and the same
instrument. Execution can be evidenced by fax signatures with original signature
pages to follow in due course.

            15.9  REFERENCES. References made in this Agreement, including use
of a pronoun, shall be deemed to include where applicable, masculine, feminine,
singular or plural, individuals, partnerships or corporations. As used in this
Agreement, "person" shall mean any natural person, corporation, partnership,
court, agency, government, board, commission, trust, estate or other entity or
authority.

            15.10 GOVERNING LAW. This Agreement and the transactions
contemplated hereby and any litigation, arbitration or dispute resolution
conducted pursuant hereto shall be construed in accordance with, and governed
by, the law of the State of Utah.

            15.11 ENTIRE AGREEMENT. This Agreement constitutes the entire
understanding among the parties, their respective partners, shareholders,
officers, directors and employees with respect to the subject matter hereof,
superseding all negotiations, prior discussions and prior agreements and
understandings relating to such subject matter.

                                      -29-
<PAGE>

            15.12 BINDING EFFECT. This Agreement shall be binding upon, and
shall inure to the benefit of, the parties hereto, and their respective
successors and assigns.

            15.13 SURVIVAL. The representations and warranties of the parties
contained in this Agreement shall survive the execution and Closing of this
Agreement for a period of one (1) year following the Closing Date. The
representations and warranties shall terminate after such date and neither Buyer
nor Seller shall have any further liability or obligation except to the extent
notice of breach thereof shall have been given prior to any such termination.
Provided however, that the foregoing shall not apply to Seller's representations
and warranties as they relate to the Retained Matters (as defined in Section
14.5), including but not limited to the representations and warranties set forth
in Section 6.2 and 6.6.

            15.14 CLOSING CONDITIONS. If the Closing occurs, all conditions of
Closing shall be deemed to have been satisfied or waived for purposes of
Closing.

            15.15 NO THIRD-PARTY BENEFICIARIES. This Agreement is intended only
to benefit the parties hereto and their respective permitted successors and
assigns.

            15.16 LIKE-KIND EXCHANGE. Notwithstanding anything contained in this
Agreement to the contrary, Seller and Buyer hereby acknowledge and agree that if
either party desires to complete the purchase of the Subject Property to effect
a qualified like-kind exchange for other property ("Exchange Property") in a
transaction that qualifies as a deferred exchange in accordance with Section
1031 of the Internal Revenue Code and regulations thereunder then each party
agrees to reasonably cooperate with the other in effecting a qualified like-kind
exchange, including the execution of reasonable documents deemed necessary to
qualify the transaction as a deferred exchange; provided, however, it is
specifically agreed that the non-exchanging party shall be an accommodating
party only and shall not incur any liability or expense as a result of such
qualified deferred exchange, and that it shall be the sole responsibility of
exchanging party to locate and identify the exchange property.

            15.17 JOINT AND SEVERAL LIABILITY. In the event Buyer asserts a
claim of indemnity or breach of representations or the terms and conditions of
this Agreement and liability is found with respect to such claim, Wasatch Oil &
Gas, LLC and Wasatch Gas Gathering, LLC shall be jointly and severally liable to
Buyer.

            15.18 INFORMATION PROVIDED BY SELLER. THE INFORMATION FURNISHED BY
SELLER TO BUYER DOES NOT PURPORT TO CONTAIN ALL OF THE INFORMATION NECESSARY TO
PROPERLY EVALUATE THIS TRANSACTION. BUYER ACKNOWLEDGES AND AGREES THAT IT WILL
CONDUCT ITS OWN INDEPENDENT ANALYSIS OF THE DATA AVAILABLE FROM PUBLIC RECORDS
AND SOURCES. ANY INFORMATION PROVIDED BY SELLER TO BUYER IS PROVIDED AS A
CONVENIENCE ONLY AND ANY RELIANCE OF BUYER ON SUCH INFORMATION SHALL BE AT
BUYER'S SOLE RISK. IN THIS CONNECTION, BUYER REPRESENTS THAT IT IS EXPERIENCED
AND KNOWLEDGEABLE IN THE OIL AND GAS INDUSTRY AND ABLE TO INDEPENDENTLY EVALUATE
THE RISKS AND BENEFITS OF ENGAGING IN THE TRANSACTIONS CONTEMPLATED BY THIS
AGREEMENT. BUYER ACKNOWLEDGES AND UNDERSTANDS THAT THE ACQUISITION AND OPERATION
OF OIL AND GAS PROPERTIES INVOLVES SUBSTANTIAL RISK, INCLUDING, WITHOUT
LIMITATION, THE LOSS OF RESERVES, REDUCED PRODUCTION RATES, LOSS OF REVENUE AND
REDUCED PRODUCT PRICE. BUYER SHALL BEAR THE FULL COST OF ANY AND ALL COSTS
ASSOCIATED WITH THE APPRAISAL, EVALUATION, EXAMINATION OR ASSIGNMENTS OF THE
ASSETS.

                                      -30-
<PAGE>

            15.19 DISCLAIMER OF REPRESENTATIONS AND WARRANTIES. EXCEPT AS
EXPRESSLY SET FORTH IN THIS AGREEMENT, THE PARTIES HERETO EACH DISCLAIM ALL
LIABILITY AND RESPONSIBILITY FOR ANY REPRESENTATION, WARRANTY, STATEMENTS OR
COMMUNICATIONS (ORALLY OR IN WRITING) TO THE OTHER PARTY (INCLUDING, BUT NOT
LIMITED TO, ANY INFORMATION CONTAINED IN ANY OPINION, INFORMATION OR ADVICE THAT
MAY HAVE BEEN PROVIDED TO ANY SUCH PARTY BY ANY PARTNER, OFFICER, STOCKHOLDER,
DIRECTOR, EMPLOYEE, AGENT, CONSULTANT, REPRESENTATIVE OR CONTRACTOR OF SUCH
DISCLAIMING PARTY OR ITS AFFILIATES OR ANY ENGINEER OR ENGINEERING FIRM, OR
OTHER AGENT, CONSULTANT OR REPRESENTATIVE) WHEREVER AND HOWEVER MADE, INCLUDING,
BUT NOT LIMITED TO, THOSE MADE IN ANY DATA ROOM AND ANY SUPPLEMENTS OR
AMENDMENTS THERETO OR DURING ANY NEGOTIATIONS. WITHOUT LIMITING THE GENERALITY
OF THE FOREGOING, SELLER MAKES NO REPRESENTATION OR WARRANTY AS TO (A) THE
AMOUNT, VALUE, QUALITY, QUANTITY, PRODUCTION OR DELIVERABILITY OF HYDROCARBONS
OR RESERVES ATTRIBUTABLE TO THE ASSETS, (B) THE PRESENT OR FUTURE VALUE OF THE
ANTICIPATED INCOME, COSTS OR PROFITS DERIVED FROM THE ASSETS OR (C) ANY
GEOLOGICAL, ENGINEERING OR OTHER INTERPRETATIONS OR ECONOMIC VALUATIONS. THE
ASSETS ARE SOLD WITHOUT ANY EXPRESS OR IMPLIED WARRANTY OF TITLE EXCEPT AS TO
PERSONS CLAIMING BY, THROUGH OR UNDER SELLER. EXCEPT AS EXPRESSLY PROVIDED IN
THIS AGREEMENT, ALL OF THE ASSETS AND ANY TANGIBLE PERSONAL PROPERTY INCLUDED IN
THE ASSETS ARE SOLD "AS IS, WHERE IS," WITH ALL FAULTS AND SELLER MAKES NO, AND
DISCLAIMS ANY, REPRESENTATION OR WARRANTY, WHETHER EXPRESS OR IMPLIED, AND
WHETHER BY COMMON LAW, STATUTE, OR OTHERWISE, AS TO (I) MERCHANTABILITY, (II)
FITNESS FOR ANY PARTICULAR PURPOSE, (III) CONFORMITY TO MODELS OR SAMPLES OF
MATERIALS OR (IV) CONDITION. THE PARTIES AGREE THAT THE PRECEDING DISCLAIMERS OF
WARRANTY ARE "CONSPICUOUS" DISCLAIMERS FOR PURPOSES OF ANY APPLICABLE LAW, RULE
OR ORDER.

THE BUYER HAS CONDUCTED, OR PRIOR TO THE CLOSING WILL CONDUCT, SUCH
INVESTIGATIONS WITH RESPECT TO THE ASSETS AS THE BUYER DEEMS ADVISABLE, AND HAS
SATISFIED, OR PRIOR TO THE CLOSING WILL SATISFY ITSELF WITH RESPECT TO THE
ASSETS, ANY SELLER PERSONAL PROPERTY AND THE TRANSACTIONS CONTEMPLATED BY THIS
AGREEMENT. EXCEPT AS EXPRESSLY PROVIDED IN THIS AGREEMENT, THE BUYER SHALL AND
HEREBY RELEASES THE SELLER FROM, AND WAIVES ANY CLAIM AGAINST THE SELLER FOR,
ANY LIABILITY OR OBLIGATION REGARDING OR FOR ANY AND ALL ENVIRONMENTAL
CONDITIONS OR HAZARDOUS MATERIALS ON OR ABOUT THE SUBJECT PROPERTY. FURTHER,
NOTWITHSTANDING ANY OTHER TERM OR CONDITION OF THIS AGREEMENT, THE BUYER SHALL
AND HEREBY RELEASES THE SELLER FROM, AND WAIVES ANY CLAIM AGAINST THE SELLER
FOR, ANY LIABILITY OR OBLIGATION REGARDING OR FOR ANY AND ALL ENVIRONMENTAL
CONDITION OR HAZARDOUS MATERIAL ON OR ABOUT THE SUBJECT PROPERTY.

                                      -31-
<PAGE>

FOR THE PURPOSES OF THIS AGREEMENT, "ENVIRONMENTAL CONDITION" MEANS (I)
CONTAMINATION OR POLLUTION OF SOIL, AIR, OR SURFACE OR GROUNDWATERS, (II) THE
DISPOSAL, PLACEMENT, EXISTENCE, PRESENCE OR RELEASE OR THREAT OF RELEASE OF A
HAZARDOUS MATERIAL AND THE AFFECT THEREOF, (III) NONCOMPLIANCE WITH OR VIOLATION
OF APPLICABLE LAW INCLUDING, WITHOUT LIMITATION, ANY LACK OR REQUIRED
GOVERNMENTAL PERMITS OR APPROVALS, "HAZARDOUS MATERIAL" MEANS (I) ANY SUBSTANCE,
THE PRESENCE OF WHICH REQUIRES INVESTIGATION, REMEDIATION, OR OTHER RESPONSE OR
CORRECTIVE ACTION UNDER APPLICABLE LAW, OR (II) ANY SUBSTANCE WHICH IS DEFINED
AS A HAZARDOUS WASTE, HAZARDOUS SUBSTANCE, EXTREMELY HAZARDOUS SUBSTANCE,
HAZARDOUS MATERIAL, HAZARDOUS MATTER, HAZARDOUS CHEMICAL, TOXIC SUBSTANCE, TOXIC
CHEMICAL, POLLUTANT OR CONTAMINANT, OR OTHER SIMILAR TERM, IN OR PURSUANT TO
APPLICABLE LAW, OR (III) ANY ASBESTOS OR ASBESTOS-CONTAINING MATERIAL, PCBS OR
EQUIPMENT OR ARTICLES CONTAINING PCBS, PETROLEUM, DIESEL FUEL, GASOLINE OR OTHER
PETROLEUM HYDROCARBONS, AND "APPLICABLE LAW" MEANS ALL EXISTING FEDERAL, STATE
OR LOCAL LAWS, COMMON LAW, STATUTES OR REGULATIONS, INCLUDING, WITHOUT
LIMITATION, THOSE RELATING TO THE PROTECTION OF HUMAN HEALTH AND SAFETY,
PROTECTION OF THE ENVIRONMENT, OR PREVENTION OF POLLUTION.

            15.20 DISPUTE RESOLUTION. If the parties are unable to resolve a
dispute as to the any matter arising under this Agreement, then, upon 15 days
notice of either party, the parties shall submit the dispute to binding
arbitration in Sale Lake County, Utah, to be conducted by an arbitrator mutually
agreeable by Seller and Buyer in accordance with the following procedures. If
Seller and Buyer cannot mutually agree on the selection of an arbitrator after
30 days, the arbitrator shall be selected by the American Arbitration
Association. No later than 30 days after initiating the arbitration procedure,
the arbitrator shall conduct a hearing, at which time the parties shall present
such evidence and witnesses as they may choose, with or without counsel.
Adherence to formal rules of evidence shall not be required, but the arbitrator
shall consider any evidence and testimony that it determines to be relevant, in
accordance with procedures that it determines to be appropriate. The arbitrator
shall render its decision specifically addressing and resolving the matter in
dispute within 15 days after the hearing. A decision may be filed in any court
of competent jurisdiction and may be enforced by any party as a final judgment
of such court.

            15.21 LIMITATION OF LIABILITY. In no event shall either party be
liable to the other for special, indirect, incidental or consequential damages,
whether arising in contract, tort or otherwise (including negligence, warranty
and strict liability); provided, however, that this limitation shall not apply
to the obligations of the parties under Section 14.

                  Executed on the dates set forth in the acknowledgments below
but effective as of the Effective Time.

SELLER:                                                 BUYER:

WASATCH OIL & GAS, LLC                                  BILL BARRETT CORPORATION

                                      -32-
<PAGE>

By /s/ Todd D. Cusick                       By  /s/ Fredrick J. Barrett
   ------------------                           -----------------------
   Todd D. Cusick                           Name:  Fredrick J. Barrett
   President                                Title:  President

WASATCH GAS GATHERING, LLC

By /s/ Todd D. Cusick
   ------------------
   Todd D. Cusick
   President

WASATCH GROUP, LLC

By /s/ Todd D. Cusick
   ------------------
   Todd D. Cusick
   President

                                      -33-

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