EXHIBIT 10.5

SECURITY AGREEMENT

                This Security Agreement (this “Agreement”) is executed as of
October 5, 2007, by and among TATONKA OIL AND GAS COMPANY, INC., a Colorado
corporation (the “Company”), TATONKA OIL AND GAS, INC., a Colorado corporation
(the “Parent” and together with the Company, the “Debtors” and individually, a
“Debtor”), and ENERGY CAPITAL SOLUTIONS, L.P., a Texas limited partnership, as
collateral agent for the Secured Parties (the “Collateral Agent”).

                FOR VALUABLE CONSIDERATION, the receipt and adequacy of which
are hereby acknowledged, each Debtor hereby covenants and agrees with the
Collateral Agent, for the benefit of the Secured Parties, as follows:

                1. Reference to Purchase Agreement and Notes. This Agreement is
being executed and delivered in connection with that certain Securities Purchase
Agreement (the “Purchase Agreement”), of even date herewith, by and among the
Parent, the Company and the Purchasers named therein (each, together with their
successors and permitted assigns, a “Secured Party” and collectively, the
“Secured Parties”), and in connection with the issuance by the Company of the
Notes pursuant to the Purchase Agreement. Capitalized terms used in this
Agreement but not otherwise defined herein shall have the meanings ascribed to
such terms in the Purchase Agreement.

                2. Incorporation of Purchase Agreement and Notes. The terms,
conditions, and provisions of the Purchase Agreement and the Notes are
incorporated herein by reference, the same as if set forth herein verbatim,
which terms, conditions, and provisions shall continue to be in full force and
effect hereunder until each Note is paid and performed in full.

                3. Certain Definitions. As used herein, the following terms have
the meanings indicated:

                                Collateral shall mean all of the following
property (including all right, title and interest of the Debtors therein):

                                (i) All present and future accounts, chattel
paper, documents, instruments, deposit accounts, general intangibles (including
any right to payment for goods sold or services rendered arising out of the sale
or delivery of personal property or work done or labor performed by the Debtors)
and investment property, now or hereafter owned, held or acquired by the
Debtors, together with any and all books of account, customer lists and other
records relating in any way to the foregoing (including, without limitation,
computer software, whether on tape, disk, card, strip, cartridge or any other
form), and in any case where an account arises from the sale of goods, the
interest of the Debtors in such goods;

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                                (ii) All present and hereafter acquired
inventory (including, without limitation, all raw materials, work in process and
finished goods) held, possessed, owned, held on consignment or held for sale,
lease, return or to be furnished under contracts of services, in whole or in
part, by the Debtors wherever located, and all records relating in any way to
the foregoing (including, without limitation, any computer software, whether on
tape, disk, card, strip, cartridge or any other form);

                                (iii) All equipment and fixtures of whatsoever
kind and character now or hereafter possessed, held, acquired, leased or owned
by the Debtors and used or usable in the Debtors’ business, together with all
replacements, accessories, additions, substitutions and accessions to all of the
foregoing, all records relating in any way to the foregoing (including, without
limitation, any computer software, whether on tape, disk, card, strip, cartridge
or any other form). To the extent that the foregoing property is located on,
attached to, annexed to, related to, or used in connection with, or otherwise
made a part of, and is or shall become fixtures upon, real property, such real
property and the record owner thereof is described on Exhibit “A” attached
hereto and made a part hereof; and

                                (iv) All interest, increase, additions,
renewals, substitutions, products and proceeds, in cash or otherwise, of any of
the property described in the foregoing clauses (i) through (iii) and all liens,
security, rights, remedies and claims of the Debtors with respect thereto.

                The term Collateral, as used herein, shall also include all
PRODUCTS and PROCEEDS of all of the foregoing (including, without limitation,
insurance payable by reason of loss or damage to the foregoing property) and any
property, securities, guaranties or monies of the Debtors which may at any time
come into the possession of the Secured Party (as hereinafter defined). The
designation of proceeds does not authorize the Debtors to sell, transfer or
otherwise convey any of the foregoing property except hydrocarbons or finished
goods intended for sale in the ordinary course of the Debtors’ business or as
otherwise provided herein.

                Default means the occurrence of any one or more of the following
events, which in the case of clause (ii) below continues for a period of 5 days
after the Collateral Agent gives written notice thereof: (i) an Event of Default
(as defined in the Notes); (ii) except as otherwise provided in this definition,
the failure of any Debtor to perform any material covenant, agreement, or
condition contained herein; (iii) the levy against the Collateral, or any part
thereof, or any execution, attachment, sequestration, or other writ; (iv) the
appointment of a receiver with respect to the Collateral, or any part thereof;
(v) the filing by any Debtor, by way of petition or answer, of any petition or
other pleading seeking relief as a debtor, or an adjustment of any Debtor’s
debts, or any other relief under any bankruptcy, reorganization, or insolvency
laws now or hereafter existing; or (vi) the receipt by the Collateral Agent of
information establishing that any representation or warranty made by any Debtor
herein is false, misleading, or erroneous in any material respect.

                Obligations means each Debtor’s payment and performance under
this Agreement, the Purchase Agreement and the Notes, together with any and all
renewals,

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extensions, and modifications of the same, whether on account of principal,
interest, fees, indemnities, costs, expenses, costs of collection thereunder or
otherwise.

                Obligor means any person obligated with respect to any of the
Collateral, whether as an account debtor, obligor on an instrument, issuer of
securities, or otherwise.

                 Security Interest means the security interest granted and the
pledge and assignment made under Paragraph 4.

                UCC means the Uniform Commercial Code as enacted in the State of
Colorado, or other applicable jurisdiction, as amended at the time in question.

                4. Security Interest. In order to secure the full and complete
payment and performance of the Obligations when due, each Debtor hereby grants
to the Collateral Agent, for the ratable benefit of the Secured Parties, a
security interest in and to the Collateral and pledges and assigns the
Collateral to the Collateral Agent, for the ratable benefit of the Secured
Parties. Such security interest is granted and such pledge and assignment are
made as security only and shall not subject the Collateral Agent to, or transfer
or in any way affect or modify, any obligation of any Debtor with respect to any
of the Collateral or any transaction involving or giving rise thereto.

                5. Representations, Warranties and Covenants of Debtors

                                 (a) Representations and Warranties with Respect
to the Collateral. Each Debtor represents and warrants that (i) it has all
requisite power and authority to enter into this Agreement; (ii) except for any
financing statement that may be filed by the Collateral Agent, for the ratable
benefit of the Secured Parties, with respect to the Collateral, no financing
statement covering the Collateral, or any part thereof, has been filed with any
filing officer or agency; (iii) no other security agreement covering the
Collateral, or any part thereof, has been made and other than (A) a statement of
lien filed by James T. Priestley d/b/a Black Diamond Mud in the books and
records of Moffat County, Colorado (Ref. No. 20073107), and (B) the one created
herein, no security interest has attached to or been perfected in the Collateral
or in any part thereof; (iv) on the date hereof each Debtor’s business address,
jurisdiction of organization and identification number from such jurisdiction of
organization is specified on Schedule 1 hereto, and (v) no dispute, right of
setoff, counterclaim, or defense exists with respect to any part of the
Collateral.

                                 (b) Affirmative Covenants of Debtors. Each
Debtor covenants and agrees to each and all of the following: (i) to execute and
deliver promptly to the Collateral Agent all such other assignments,
certificates, and supplemental writings, and to do all other acts or things, as
the Collateral Agent may reasonably request in order more fully to evidence and
perfect the security interest created herein; (ii) to furnish the Collateral
Agent promptly with any information or writing that the Collateral Agent may
reasonably request concerning the Collateral; (iii) to allow the Collateral
Agent to inspect all books and records of any Debtor relating to the Collateral
or the Notes; (iv) to notify the Collateral Agent promptly of any change in any
material fact or circumstance warranted or represented by any Debtor in this
Agreement or in any other writings furnished by any Debtor to the Collateral
Agent in connection with the Collateral; (v) to notify the Collateral Agent
promptly of any claim, action, or proceeding

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affecting title to the Collateral, or any part thereof, or the security interest
therein, and at the request of the Collateral Agent, to appear in and defend, at
Debtors’ sole cost and expense, any such action or proceeding; (vi) to maintain
insurance customarily obtained by similar businesses and (vii) to pay to the
Collateral Agent promptly the amount of all costs and expenses (including
reasonable attorney’s fees) incurred by the Collateral Agent in the enforcement
of their rights hereunder.

                                (c) Negative Covenants of Debtors. Each Debtor
covenants and agrees that, without the prior written consent of the Collateral
Agent (which consent may be granted or withheld in the sole and absolute
discretion of the Collateral Agent), such Debtor will not (i) except for sales
of inventory in the ordinary course of business consistent with past practice,
sell, assign, or transfer the Collateral or any of its rights therein, (ii)
create any other security interest in, mortgage, or otherwise encumber the
Collateral or any part thereof, or permit the Collateral to be or become subject
to any lien, attachment, execution, sequestration, other legal or equitable
process, or any encumbrance of any kind or character, except the security
interest created herein or disclosed herein, or (iii) change its jurisdiction of
organization, name or corporate structure.

                6. Default; Remedies. Should a Default occur and be continuing,
the Collateral Agent may, at its election, exercise any and all rights available
to the Collateral Agent and the Secured Parties under the UCC, in addition to
any and all other rights afforded by this Agreement, at law, in equity, or
otherwise, including, without limitation, (a) to the extent practicable,
requiring any Debtor to assemble all or part of the Collateral and make it
available to the Collateral Agent at a place to be designated by the Collateral
Agent which is reasonably convenient to such Debtor and the Collateral Agent,
(b) applying by appropriate judicial proceedings for appointment of an
independent receiver for all or part of the Collateral (and each Debtor hereby
consents to any such appointment), and (d) applying to the Obligations any cash
held by the Collateral Agent under this Agreement.

                                (a) Notice. Reasonable notification of the time
and place of any public sale of the Collateral, or reasonable notification of
the time after which any private sale or other intended disposition of the
Collateral is to be made, shall be sent to Debtors and to any other person
entitled to notice under the UCC; provided that if any of the Collateral
threatens to decline speedily in value or is of the type customarily sold on a
recognized market, the Collateral Agent may sell or otherwise dispose of the
Collateral in a commercially reasonable transaction without notification,
advertisement, or other notice of any kind. It is agreed that notice sent or
given not less than five calendar days prior to the taking of the action to
which the notice relates is reasonable notification and notice for the purposes
of this subparagraph.

                                (b) Sales of Securities. In connection with the
sale of any Collateral that is securities, the Collateral Agent is authorized,
but not obligated, to limit prospective purchasers to the extent deemed
necessary or desirable by the Collateral Agent to render such sale exempt from
the registration requirements of the Securities Act of 1933, as amended, and any
applicable state securities laws, and no sale so made in good faith by the
Collateral Agent shall be deemed not to be “commercially reasonable” because so
made.

                                (c) Application of Proceeds. The Collateral
Agent shall apply the proceeds of any sale or other disposition of the
Collateral under this Paragraph 6 in the following order: first,

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to the payment of all its reasonable expenses incurred in retaking, holding, and
preparing any of the Collateral for sale(s) or other disposition, in arranging
for such sale(s) or other disposition, and in actually selling or disposing of
the same (all of which are part of the Obligations); second, toward repayment of
any other amounts reasonably expended by the Collateral Agent under this
Agreement; and third, toward payment of the balance of the Obligations on a pro
rata basis. Any surplus remaining shall be delivered to Debtors or as a court of
competent jurisdiction may direct.

                7. Other Rights.

                                (a) Performance. In the event any Debtor shall
fail to pay when due all taxes on any of the Collateral, or to preserve the
priority of the Security Interest in any of the Collateral, or otherwise fail to
perform any of its obligations under this Agreement with respect to the
Collateral, then the Collateral Agent may, at its option, but without being
required to do so, pay such taxes, prosecute or defend any suits in relation to
the Collateral, or take all such other action which any Debtor is required, but
has failed or refused, to take under this Agreement. Any sum which may be
expended or paid by the Collateral Agent under this subparagraph (including,
without limitation, court costs and attorneys’ fees) shall bear interest from
the dates of expenditure or payment at the Interest Rate pursuant to the Note
until paid and, together with such interest, shall be payable by each Debtor to
the Collateral Agent upon demand and shall be part of the Obligations.

                                (b) Collection. If there exists an uncured Event
of Default, then upon notice from the Collateral Agent, each Obligor with
respect to any payments on any of the Collateral (including, without limitation,
dividends and other distributions with respect to securities and insurance
proceeds payable by reason of loss or damage to any of the Collateral) is hereby
authorized and directed by each Debtor to make payment directly to the
Collateral Agent, for the benefit of the Secured Parties, regardless of whether
any Debtor was previously making collections thereon. Subject to Paragraph 7(e)
hereof, until such notice is given, each Debtor is authorized to retain and
expend all payments made on the Collateral. If there exists an uncured Event of
Default, then the Collateral Agent shall have the right in its own name or in
the name of any Debtor to compromise or extend time of payment with respect to
all or any portion of the Collateral for such amounts and upon such terms as the
Collateral Agent may reasonably determine; to demand, collect, receive, receipt
for, sue for, compound, and give acquittances for any and all amounts due or to
become due with respect to the Collateral; to take control of cash and other
proceeds of any Collateral; to endorse the name of any Debtor on any notes,
acceptances, checks, drafts, money orders, or other evidences of payment on the
Collateral that may come into the possession of the Collateral Agent; to sign
the name of any Debtor on any invoice or bill of lading relating to any
Collateral, on any drafts against Obligors or other persons making payment with
respect to the Collateral, on assignments and verifications of accounts or other
Collateral and on notices to Obligors making payment with respect to the
Collateral; to send requests for verification of obligations to any Obligor; and
to do all other acts and things necessary to carry out the intent of this
Agreement. If there exists an uncured Event of Default, then if any Obligor
fails or refuses to make payment on any Collateral when due, the Collateral
Agent is authorized, in its sole discretion, either in its own name or in the
name of any Debtor, to take such action as the Collateral Agent shall deem
appropriate for the collection of any amounts owed with respect to the
Collateral or upon which a delinquency exists. Regardless of any other

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provision hereof, however, the Collateral Agent shall never be liable for its
failure to collect, or for its failure to exercise diligence in the collection
of, any amounts owed with respect to the Collateral, nor shall it be under any
duty whatever to anyone except Debtors to account for funds that they shall
actually receive hereunder. Without limiting the generality of the foregoing,
the Collateral Agent shall have no responsibility for ascertaining any
maturities, calls, conversions, exchanges, offers, tenders, or similar matters
relating to any Collateral, or for informing any Debtor with respect to any of
such matters (irrespective of whether the Collateral Agent actually has, or may
be deemed to have, knowledge thereof). The rights granted to the Collateral
Agent under this subparagraph may be exercised at any time, whether or not a
Default has occurred and is continuing.

                                (c) Voting of Securities. As long as a Default
has not occurred and is not continuing, Debtors shall be entitled to exercise
all voting rights pertaining to any Collateral that is securities. After the
occurrence and during the continuance of a Default, the right to vote any
Collateral that is securities shall be vested exclusively in the Collateral
Agent. To this end, each Debtor hereby irrevocably constitutes and appoints the
Collateral Agent the proxy and attorney-in-fact of such Debtor, with full power
of substitution, to vote, and to act with respect to, any and all Collateral
that is securities standing in the name of such Debtor or with respect to which
such Debtor is entitled to vote and act, subject to the understanding that such
proxy may not be exercised unless a Default has occurred and is continuing. The
proxy herein granted is coupled with an interest, is irrevocable, and shall
continue until the Obligations have been paid and performed in full.

                                (d) Certain Proceeds. Notwithstanding any
provision of this Agreement to the contrary, any and all stock dividends or
distributions in property made on or in respect of any Collateral that is
securities, and any proceeds of any Collateral that is securities, whether such
dividends, distributions, or proceeds result from a subdivision, combination, or
reclassification of the outstanding capital stock of any issuer thereof or as a
result of any merger, consolidation, acquisition, or other exchange of assets to
which any issuer may be a party, or otherwise, shall be part of the Collateral
hereunder, and shall, if received by any Debtor, be held in trust for the
Collateral Agent, for the benefit of the Secured Parties. Upon notice from the
Collateral Agent, such dividends, distributions or other proceeds shall
forthwith be delivered to the Collateral Agent (accompanied by proper
instruments of assignment and/or stock and/or bond powers executed by such
Debtor in accordance with the Collateral Agent’s instructions) to be held
subject to the terms of this Agreement. Any cash proceeds of Collateral which
come into the possession of the Collateral Agent (including, without limitation,
insurance proceeds) may, at the Collateral Agent’s option, be applied in whole
or in part to the Obligations (to the extent then due), be released in whole or
in part to or on the written instructions of Debtors for any general or specific
purpose, or be retained in whole or in part by the Collateral Agent as
additional Collateral. Any cash Collateral in the possession of the Collateral
Agent may be invested by the Collateral Agent in certificates of deposit of a
term of 12 months or less issued by any state or national bank having combined
capital and surplus greater than $100,000,000, or in securities issued or
guaranteed by the United States of America or any agency thereof that mature
within a year of the date of acquisition thereof. The Collateral Agent shall
never be obligated to make any such investment and shall never have any
liability to any Debtor for any loss that may result therefrom. All interest and
other amounts earned from any investment of Collateral may be dealt

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with by the Collateral Agent in the same manner as other cash Collateral. The
provisions of this subparagraph shall be applicable whether or not a Default has
occurred and is continuing.

                                (e) Subrogation. If any of the Obligations is
given in renewal or extension or applied toward the payment of indebtedness
secured by any lien, the Collateral Agent, for the ratable benefit of the
Secured Parties shall be, and is hereby, subrogated to all of the rights,
titles, interests, and liens securing the indebtedness so renewed, extended, or
paid.

                                (f) Indemnification. Each Debtor, jointly and
severally, agrees to indemnify, save, and hold the Collateral Agent and the
Secured Parties harmless from and against, and covenants to defend the
Collateral Agent and the Secured Parties against, any and all losses, damages,
claims, costs, penalties, liabilities, and expenses, including, without
limitation, court costs and attorneys’ fees, howsoever arising or incurred
because of, incident to, or with respect to the Collateral or any use,
possession, maintenance, or management thereof and the execution, delivery,
enforcement, performance and administration of this Agreement other than to the
extent such losses, damages, claims, costs, penalties, liabilities, and expenses
are caused by such person’s gross negligence or willful misconduct.

                                (g) Duty of Collateral Agent. The Collateral
Agent’s sole duty with respect to the custody, safekeeping and physical
preservation of the Collateral in its possession, under Section 9-207 of the UCC
or otherwise, shall be to deal with it in the same manner as the Collateral
Agent deals with similar property for its own account. Neither the Collateral
Agent, any Secured Party nor any of their respective officers, directors,
employees or agents shall be liable for failure to demand, collect or realize
upon any of the Collateral or for any delay in doing so or shall be under any
obligation to sell or otherwise dispose of any Collateral upon the request of
any Debtor or any other person or to take any other action whatsoever with
regard to the Collateral or any part thereof. The power conferred on the
Collateral Agent and the Secured Parties hereunder are solely to protect the
Collateral Agent’s and the Secured Parties’ interests in the Collateral and
shall not impose any duty upon the Collateral Agent or any Secured Party to
exercise any such powers. The Collateral Agent and the Secured Parties shall be
accountable only to the Debtors and only for amounts that they actually receive
as a result of the exercise of such powers, and neither they nor any of their
officers, directors, employees or agents shall be responsible to any Debtor for
any act or failure to act hereunder, except for their own gross negligence or
willful misconduct.

                8. Miscellaneous.

                                (a) Term. Upon full and final payment in cash
and performance of the Obligations, this Agreement (other than Paragraph 7(g)
hereof) shall thereafter terminate upon receipt by the Collateral Agent of the
Company’s written notice of such termination.

                                (b) Actions Not Releases. The Security Interest
and each Debtor’s Obligations and the Collateral Agent’s and the Secured
Parties’ rights hereunder shall not be released, diminished, impaired, or
adversely affected by the occurrence of any one or more of the following events:
(i) the taking or accepting of any other security or assurance for any or all of
the Obligations; (ii) any release, surrender, exchange, subordination, or loss
of any security or assurance at any time existing in connection with any or all
of the Obligations; (iii) the

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modification of, amendment to, or waiver of compliance with any terms of this
Agreement without the notification or consent of any Debtor, except as required
herein; (iv) the insolvency, bankruptcy, or lack of corporate, partnership or
trust power of any party at any time liable for the payment of any or all of the
Obligations, whether now existing or hereafter occurring; (v) any renewal,
extension, or rearrangement of the payment of any or all of the Obligations,
either with or without notice to or consent of any Debtor, or any adjustment,
indulgence, forbearance, or compromise that may be granted or given by the
Collateral Agent to any Debtor; (vi) any neglect, delay, omission, failure, or
refusal of the Collateral Agent to take or prosecute any action in connection
with this Agreement or any other agreement, document, guaranty, or instrument
evidencing, securing, or assuring the payment of all or any of the Obligations;
(vii) any failure of the Collateral Agent to notify any Debtor of any renewal,
extension, or assignment of the Obligations or any part thereof, or the release
of any security, or of any other action taken or refrained from being taken by
the Collateral Agent against any Debtor or any new agreement between Secured
Parties and any Debtor, it being understood that the Collateral Agent shall not
be required to give Debtor any notice of any kind under any circumstances
whatsoever with respect to or in connection with the Obligations, including,
without limitation, notice of acceptance of this Agreement or any Collateral
ever delivered to or for the account of the Collateral Agent hereunder; (viii)
the illegality, invalidity, or unenforceability of all or any part of the
Obligations against any party obligated with respect thereto by reason of the
fact that the Obligations, or the interest paid or payable with respect thereto,
exceeds the amount permitted by law, the act of creating the Obligations, or any
part thereof, is ultra vires, or the officers, partners, or trustees creating
same acted in excess of their authority, or for any other reason; or (ix) if any
payment by any party obligated with respect thereto is held to constitute a
preference under applicable laws or for any other reason the Collateral Agent is
required to refund such payment or pay the amount thereof to someone else.

                                (c) Waivers. Except to the extent expressly
otherwise provided herein, each Debtor waives (i) any right to require the
Collateral Agent or Secured Parties to proceed against any other person, to
exhaust their rights in the Collateral, or to pursue any other right which the
Collateral Agent or Secured Parties may have; (ii) with respect to the
Obligations, presentment and demand for payment, protest, notice of protest and
nonpayment, and notice of the intention to accelerate; and (iii) all rights of
marshaling in respect of any and all of the Collateral.

                                (d) Financing Statement. The Collateral Agent
shall be entitled at any time to file this Agreement or a carbon, photographic,
or other reproduction of this Agreement, as a financing statement, but the
failure of the Collateral Agent to do so shall not impair the validity or
enforceability of this Agreement.

                                (e) Amendments. This instrument may be amended
only by an instrument in writing executed jointly by each Debtor and the
Collateral Agent, and supplemented only by documents delivered or to be
delivered in accordance with the express terms hereof; provided that the
Collateral Agent shall only be permitted to enter into any amendment that
releases all or substantially all of the Collateral or releases any Debtor from
its obligations hereunder upon the written direction of the holders of more than
50% of the then outstanding aggregate principal amount of the Notes.

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                                (f) Multiple Counterparts. This Agreement has
been executed in a number of identical counterparts, each of which shall be
deemed an original for all purposes and all of which constitute, collectively,
one agreement; but, in making proof of this Agreement, it shall not be necessary
to produce or account for more than one such counterpart.

                                (g) Parties Bound; Assignment. This Agreement
shall be binding on Debtors each of their successors and permitted assigns and
shall inure to the benefit of the Collateral Agent and the Secured Parties and
their respective successors and assigns. No Debtor may, without the prior
written consent of the Collateral Agent, assign any rights, duties, or
obligations hereunder. In the event of an assignment of all or part of the
Obligations, the Security Interest and other rights and benefits hereunder, to
the extent applicable to the part of the Obligations so assigned, shall be
transferred therewith.

                                (h) Governing Law; Exclusive Jurisdiction. This
Agreement shall be governed by and construed in accordance with the internal
laws of the State of Colorado, without giving effect to the choice of law
provisions. This Agreement shall not be interpreted or construed with any
presumption against the party causing this Agreement to be drafted. Each Debtor,
the Collateral Agent and each Secured Party (i) hereby irrevocably submit to the
exclusive jurisdiction of the United States District Court sitting in the
Northern District of Texas and the courts of the State of Texas located in
Dallas, Texas, for the purposes of any suit, action or proceeding arising out of
or relating to this Agreement or the transactions contemplated hereby, and (ii)
hereby waive, and agree not to assert in any such suit, action or proceeding,
any claim that it is not personally subject to the jurisdiction of such court,
that the suit, action or proceeding is brought in an inconvenient forum or that
the venue of the suit, action or proceeding is improper.

                                (i) Complete Agreement. This Agreement, the
Purchase Agreement, the Notes, and all other agreements, instruments or
documents executed and/or delivered in connection therewith are intended by
Debtors and the Collateral Agent as a final expression of their agreement with
respect to the subject matter hereof and thereof, and supersede all prior
agreements and understandings whether oral or written with respect to the
subject matter hereof and thereof.

[Remainder of page intentionally left blank.]

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     IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
duly executed by their respective authorized officers as of the date first above
written.

“Debtors”:    TATONKA OIL AND GAS, INC.        By: 
____________________________________________________________ Name: 
_________________________________________________________ Title: 
___________________________________________________________     TATONKA OIL AND
GAS COMPANY,  INC.        By: 
____________________________________________________________ Name: 
_________________________________________________________ Title: 
___________________________________________________________     “Collateral
Agent”:    ENERGY CAPITAL SOLUTIONS, L.P.          By: 
____________________________________________________________ Name: 
__________________________________________________________ Title: Authorized
Signatory 

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Schedule 1

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              Jurisdiction of    Organization  Name of Debtor    Address   
Organization    Number 

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  Tatonka Oil and Gas Company, Inc.    950 Seventeenth Street, Suite 2300   
Colorado    20041083534      Denver, CO 80202         

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  Tatonka Oil and Gas, Inc.    950 Seventeenth Street, Suite 2300    Colorado   
20011104066      Denver, CO 80202         

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