Filed by Bowne Pure Compliance





Exhibit 10.1




FIRST AMENDMENT TO NOTE PURCHASE AGREEMENT




THIS FIRST AMENDMENT TO NOTE PURCHASE AGREEMENT (this “Amendment”) is dated as of
September 44[_____], 2008, by and among Rio Vista Penny LLC, an Oklahoma limited liability company
(“Company”), TCW Asset Management Company, as administrative agent (“Administrative
Agent”), and the Holders party to the Original Agreement defined below (“Holders”).



W I T N E S S E T H:




WHEREAS, Company, Administrative Agent and Holders entered into that certain Note Purchase
Agreement dated as of November 19, 2007 (as amended, supplemented, or restated to the date hereof,
the “Original Agreement”), for the purpose and consideration therein expressed, whereby
Holders became obligated to make loans to Company as therein provided; and



WHEREAS, Company, Administrative Agent and Holders desire to further amend the Original
Agreement as set forth herein;



NOW, THEREFORE, in consideration of the premises and the mutual covenants and agreements
contained herein and in the Original Agreement, in consideration of the loans which may hereafter
be made by Holders to Company, and for other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the parties hereto do hereby agree as follows:



ARTICLE I.




DEFINITIONS AND REFERENCES




Section 1.1. Terms Defined in the Original Agreement. Unless the context otherwise
requires or unless otherwise expressly defined herein, the terms defined in the Original Agreement
shall have the same meanings whenever used in this Amendment.



Section 1.2. Other Defined Terms. Unless the context otherwise requires, the
following terms when used in this Amendment shall have the meanings assigned to them in this
Section 1.2.




“Amendment” means this First Amendment to Note Purchase Agreement.




“Amendment Documents” means this Amendment and all other Note Documents
executed and delivered in connection herewith.





[First Amendment to

Note Purchase Agreement]




 


 









 






“Designated Defaults” means the following Defaults or Events of Default that
have occurred as of the date of this Amendment and are continuing under the Note Purchase
Agreement:




(a) Company’s entering into the Hedging Contracts described in Schedule 1 hereto
without the prior written consent of Administrative Agent;




(b) Company’s failure to deliver audited financial statements for the Fiscal Year
ending December 31, 2007, as required by Section 7.2(a) of the Note Purchase Agreement;




(c) Company’s failure to deliver financial statements for the Fiscal Quarters ending
March 31, 2008, and June 30, 2008, in each case as required by Section 7.2(b) of the Note
Purchase Agreement;




(d) Company’s failure to comply with Section 7.4(b) of the Note Purchase Agreement by
notifying each Holder Party in writing of the occurrence of such Defaults or Events of
Default under the Note Purchase Agreement;




(e) Company’s incurrence of capital expenditures not included in the APOD, as then in
effect, but which are included in the new APOD attached hereto as Schedule 6; and




(f) Company’s failure to deliver an Engineering Report, effective as of May 1, 2008, in
compliance with the provisions of Section 7.2(i) of the Note Purchase Agreement.




“Note Purchase Agreement” means the Original Agreement as amended hereby.




“Released Claims” means any and all actions, causes of action, judgments,
executions, suits, debts, claims, demands, controversies, liabilities, obligations, damages
and expenses of any and every character (whether known or unknown, liquidated or
unliquidated, absolute or contingent, acknowledged or disputed, direct or indirect), at law
or in equity, of whatsoever kind or nature (including claims of usury), whether heretofore
or hereafter accruing, for or because of any matter or things done, omitted or suffered to
be done by any of the Released Persons prior to and including the date hereof that in any
way directly or indirectly arise out of or in any way are connected to (a) any of the Note
Documents or any default or event of default thereunder, (b) any negotiation, discussion,
enforcement action, agreement or failure to agree related to any Note Document or any
default or event of default thereunder, or (c) any action, event, occurrence, or omission
otherwise related to the rights, duties, obligations and relationships among the various
Related Parties and Seller Parties.




“Released Persons” means Administrative Agent, Holders, and Royalty Owner,
together with their respective employees, agents, attorneys, officers, partners,
shareholders, accountants, consultants, and directors, and their respective successors and
assigns.



[First Amendment to

Note Purchase Agreement]





 


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ARTICLE II.




AMENDMENTS & WAIVERS





Section 2.1. Interest Rate.



(a) The following definitions in Section 1.1 of the Original Agreement are hereby amended in
their entirety to read as follows:




“Fixed Rate” means the rate of twelve and one-half percent (12.50%) per annum;
provided that such per annum rate shall be reduced to ten and one-half percent (10.50%) per
annum on the Recalculation Date, if any.




“Hedging Contract” means (a) any agreement providing for options, swaps,
floors, caps, collars, forward sales or forward purchases (including any agreement for the
sale or purchase of hydrocarbons that provides a fixed price for more than two months of
production or deliveries) involving interest rates, commodities or commodity prices,
equities, currencies, bonds, or indexes based on any of the foregoing, (b) any option,
futures or forward contract traded on an exchange, and (c) any other derivative agreement or
other similar agreement or arrangement.



(b) The following definitions are hereby added to Section 1.1 of the Original Agreement in
appropriate alphabetical order to read as follows:




“Effective Rate Certificate” as defined in Section 2.6(a).




“Existing Litigation” means, collectively, the following litigation: (a)
Northport Production Company and Eugene A. Viele, plaintiffs, vs. Rio Vista Energy Partners,
L.P., Rio Vista GP, L.L.C., Rio Vista Penny, L.L.C., Jerome B. Richter a/k/a/ “Jerry”
Richter, and Douglas G. Manner, defendants, pending in the District Court of Dallas County,
Texas no. 08-09658, and (b) on November 20, 2007 Rio Vista Energy Partners L.P., Rio Vista
Penny LLC, Gary Moores, Bill Wood and G M Oil Properties, Inc. jointly filed an action for
declaratory relief against Energy Spectrum Advisors, Inc. in the District Court in McIntosh
County, Oklahoma, which was filed in response to Energy Spectrum’s assertion that Rio Vista
Energy Partners L.P., Rio Vista Penny LLC, as well as G M Oil Properties, Inc. owed Energy
Spectrum a commission allegedly due and owing based on Rio Vista Penny LLC’s November, 2007
purchase of certain assets from G M Oil Properties, Inc.




“Recalculation Date” means the first day of the Fiscal Quarter immediately
following the delivery of an Effective Rate Certificate that has been confirmed to the
satisfaction of Administrative Agent.



[First Amendment to

Note Purchase Agreement]





 


3









 







Section 2.2. Interest Rates. Subsection (a) of Section 2.6 of the Original Agreement
is hereby amended to add the following sentences thereto at the end of such subsection to read as
follows:




Company may request that the Fixed Rate be reduced as described in the definition thereof
immediately following the delivery of the Engineering Report prepared by the Independent
Engineer as of November 1, 2008 (the “Applicable Date”). In order to make any such
request, Company shall deliver to Administrative Agent a certificate (in form and detail
satisfactory to Administrative Agent) signed by the chief financial officer of Company (an
“Effective Rate Certificate”):




(i) certifying that no Default exists; and




(ii) certifying and demonstrating in reasonable detail that the Collateral Coverage
Ratio determined as of the Applicable Date is at least 1.5 to 1.0.”



Section 2.3. Mandatory Prepayments. Subsection (c) of Section 2.8 of the Original
Agreement is hereby amended to replace the phrase in the second sentence “May 19, 2008 through and
including November 19, 2009” with “January 1, 2009 through the Maturity Date”.




Section 2.4. Books, Financial Statements and Reports.



(a) Subsection (a) of Section 7.2 of the Original Agreement is hereby amended to replace the
phrase in the first sentence “within ninety (90) days” with “within one hundred and five (105)
days”.



(b) Subsection (b) of Section 7.2 of the Original Agreement is hereby amended to replace the
phrase in the first sentence “within forty-five (45) days after the end of each Fiscal Quarter”
with “within sixty (60) days after the end of each Fiscal Quarter (commencing with the Fiscal
Quarter ending December 31, 2008)”.



Section 2.5. Disclosure Schedule. Section 5.9 of the Disclosure Schedule is hereby
amended to include the Existing Litigation.



Section 2.6. Holders Schedule. Schedule 4 of the Original Agreement is hereby amended
in its entirety to read as set forth on Schedule 4 attached hereto.



Section 2.7. Approved Plan of Development. Schedule 6 of the Original Agreement is
hereby amended in its entirety to read as set forth on Schedule 6 attached hereto.



Section 2.8. Limited Waivers. Company has requested that Administrative Agent and
Holders waive the Designated Defaults, and Administrative Agent and Holders have agreed to do so on
the terms set forth herein. Accordingly, subject to the conditions and limitations set forth
herein, and the agreements of Company contained herein, Administrative Agent and Holders hereby
waive the Designated Defaults.



[First Amendment to

Note Purchase Agreement]





 


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ARTICLE III.




CONDITIONS OF EFFECTIVENESS




Section 3.1. Effective Date. The effectiveness of this Amendment as of the date first
above is subject to the satisfaction, or waiver in accordance with Section 12.1 of the Note
Purchase Agreement, of the following conditions:



(a) Amendment Documents. Administrative Agent shall have received counterparts of
each Amendment Document originally executed and delivered by each applicable Restricted Person and
in such numbers as Administrative Agent or its counsel may reasonably request.



(b) Good Standing Certificates. Administrative Agent shall have received a good
standing certificate from the applicable Governmental Authority of each Restricted Person’s
jurisdiction of incorporation, organization or formation, each dated a recent date.



(c) Up-Front Payment. Administrative Agent shall have received the up-front payment
that is due and payable pursuant to Section 2.6(d) of the Note Purchase Agreement.



(d) Closing Certificate. Company shall have delivered to Administrative Agent an
originally executed Closing Certificate in the form attached hereto as Exhibit A, appropriately
completed.



(e) Completion of Proceedings. All corporate, partnership, limited liability company,
and other proceedings taken or to be taken in connection with the transactions contemplated hereby
and all documents incidental thereto not previously found acceptable by Administrative Agent and
its counsel shall be reasonably satisfactory in form and substance to Administrative Agent and such
counsel, and Administrative Agent and such counsel shall have received all such counterpart
originals or certified copies of such documents as Administrative Agent may reasonably request.



(f) Other Documentation. Administrative Agent shall have received all documents and
instruments which Administrative Agent has then reasonably requested, in addition to those
described in this Section 3.1. All such additional documents and instruments shall be reasonably
satisfactory to Administrative Agent in form, substance and date.



(g) No Default. No event shall have occurred and be continuing that would constitute
an Event of Default or a Default (other than the Designated Defaults, which are being waived
pursuant to the provisions of Section 2.8).



(h) Payment of Expenses. The Holders and their counsel shall have received all fees
and other amounts due and payable on or prior to the effective date hereof with respect to this
Amendment.



[First Amendment to

Note Purchase Agreement]






 


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ARTICLE IV.




REPRESENTATIONS AND WARRANTIES




Section 4.1. Representations and Warranties of Company. In order to induce each
Holder to enter into this Amendment, Company represents and warrants to each Holder that, after
giving effect to the waivers of the Designated Defaults provided for herein:



(a) The representations and warranties contained in Article V of the Original Agreement are
true and correct at and as of the time of the effectiveness hereof, except to the extent such
representations and warranties specifically refer to an earlier date, in which case they are true
and correct as of such earlier date.



(b) Company is duly authorized to execute and deliver this Amendment and the other Amendment
Documents and is and will continue to be duly authorized to borrow monies and to perform its
obligations under the Note Purchase Agreement. Company has duly taken all corporate action
necessary to authorize the execution and delivery of this Amendment and the other Amendment
Documents and to authorize the performance of the obligations of Company hereunder and thereunder.



(c) The execution and delivery by Company of this Amendment and the other Amendment Documents,
the performance by Company of its obligations hereunder and thereunder and the consummation of the
transactions contemplated hereby and thereby do not and will not (i) conflict with any provision of
(1) any Law, (2) the organizational documents of any Restricted Person, or (3) any material
agreement, judgment, license, order or permit applicable to or binding upon any Restricted Person,
(ii) result in the acceleration of any Indebtedness owed by any Restricted Person, or (iii) result
in or require the creation of any Lien upon any assets or properties of any Restricted Person
except as expressly contemplated or permitted in the Note Documents. Except as expressly
contemplated in the Note Documents, no permit, consent, approval, authorization or order of, and no
notice to or filing with, any Governmental Authority or third party is required in connection with
the execution, delivery or performance by any Restricted Person of any Amendment Document or to
consummate any transactions contemplated thereby. Clauses (a) and (b) in the definition of
Material Contracts describe all of the Material Contracts (other than oil and gas leases) in effect
on the date hereof, and all such Material Contracts (other than oil and gas leases) are in full
force and effect and no defaults currently exist thereunder that would have a Material Adverse
Change on the Company.



(d) This Amendment, the Note Purchase Agreement, and the other Amendment Documents when duly
executed and delivered will be, legal, valid and binding obligations of Restricted Persons and each
of their respective Affiliates which is a party hereto or thereto, enforceable in accordance with
their terms except as such enforcement may be limited by bankruptcy, insolvency or similar Laws of
general application relating to the enforcement of creditors’ rights.



(e) The Initial Pro Forma Financial Statements fairly present the Consolidated financial
position at the date thereof and the Consolidated statement of operations and the changes in
Consolidated financial position for the period covered by such financial statements
for Company. Copies of such financial statements have heretofore been delivered to each
Holder. Since the Closing Date, no Material Adverse Change has occurred in the financial condition
or businesses or in the Consolidated financial condition or businesses of Company. However, since
the Closing Date, (i) Company has become involved in the Existing Litigation, (ii) Company makes no
representation or warranty as to whether the Existing Litigation constitutes a Material Adverse
Change, and (iii) the preceding sentence is so qualified by the existence of such Existing
Litigation.



[First Amendment to

Note Purchase Agreement]





 


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(f) Restricted Persons have no Deposit Accounts, except for the following Deposit Accounts
established at Bank of Eufaula, 102 N. Main, P.O. Box 607, Eufaula, OK 74432:



	 	 	 	 	 
	Rio Vista Penny, LLC — Operating Account
	 	 	#6524272	 
	Rio Vista Penny, LLC — Savings Account
	 	 	#494512	 
	Rio Vista Penny, LLC — CD #1
	 	 	#27770	 
	Rio Vista Penny, LLC — CD #2
	 	 	#27888	 
	Rio Vista Penny, LLC — Custody Account
	 	 	#6524250	 
	Rio Vista Operating, LLC – Checking
	 	 	#6524239	 
	Rio Vista Operating, LLC — Payroll Account
	 	 	#6524195	 






(g) Restricted Persons have sent a notice, in form satisfactory to Administrative Agent, to
all existing purchasers of Hydrocarbons produced from the Eligible Mortgaged Properties and/or
other Persons making payments to Restricted Persons in respect of their oil and gas business,
directing them to forward all amounts payable to Restricted Persons directly to the Collateral
Account at the mailing address of the depositary bank for deposit into the Collateral Account (or
alternatively, by wire transfer directly into the Collateral Account).



ARTICLE V.




MISCELLANEOUS





Section 5.1. Ratification; Acknowledgments; No Waiver.



(a) Ratification. The Original Agreement as hereby amended is hereby ratified and
confirmed in all respects. The Note Documents, as they may be amended or affected by the various
Amendment Documents, are hereby ratified and confirmed in all respects. Any reference to the Note
Purchase Agreement in any Note Document shall be deemed to be a reference to the Original Agreement
as hereby amended. The execution, delivery and effectiveness of this Amendment and the other
Amendment Documents shall not, except as expressly provided herein or therein, operate as a waiver
of any right, power or remedy of Holders under the Note Purchase Agreement, the Notes, or any other
Note Document nor constitute a waiver of any provision of the Note Purchase Agreement, the Notes or
any other Note Document.



(b) Acknowledgment of Designated Defaults. Company hereby acknowledges and agrees
that the Designated Defaults have occurred and are continuing and that the waiver thereof by
Required Holders, together with the other agreements in this Amendment, constitutes valuable and
sufficient consideration for Company’s execution and performance of this
Amendment. Company further represents and warrants that, as of the date hereof and after
giving effect to the waivers of the Designated Defaults set forth in this Amendment, no Defaults or
Events of Default exist under the Note Documents.



[First Amendment to

Note Purchase Agreement]





 


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(c) No Waiver. Administrative Agent and Holders require and will require strict
performance by Company and each other party to any Note Document of all of their respective
obligations, agreements and covenants contained in the Note Purchase Agreement and the other Note
Documents, and no inaction or action regarding any such breach is intended to be or shall be a
waiver thereof. In no event and under no circumstance shall any past or future discussions with
Administrative Agent or Holders and/or Administrative Agent’s or any Holder’s forbearance from
exercising any of its rights or remedies under the Note Documents: (i) cause a modification of the
Note Documents; (ii) establish a custom with respect to any of the Note Documents; (iii) operate as
a waiver of any existing or future default or event of default under the Note Documents; (iv)
entitle any Restricted Person to any other or further notice or demand whatsoever; (v) in any way
modify, change, impair, affect, diminish or release any obligations or liability of any Restricted
Person under or pursuant to the Note Documents or any other liability any such Person may have to
any Holder; or (vi) waive, limit or condition Administrative Agent’s or any Holder’s rights and
remedies under the Note Documents, all of which rights and remedies are expressly reserved.



Section 5.2. Release of Claims. To induce Holder Parties to enter into this
Agreement, each Restricted Person hereby (a) represents and warrants that as of the date of this
Agreement there are no claims or offsets against or defenses or counterclaims to its obligations
under the Note Documents, and waives any and all such claims, offsets, defenses, or counterclaims,
whether known or unknown, arising prior to the date of this Agreement, (b) releases and forever
discharges the Released Persons from any and all Released Claims, and (c) covenants not to assert
(and not to assist or enable any other Person to assert) any Released Claim against any Released
Person. The Restricted Persons acknowledge and agree that such release is a general release of any
and all Released Claims that constitutes a full and complete satisfaction for all or any alleged
injuries or damages arising out of or in connection with the Released Claims, all of which are
herein compromised and settled.



Section 5.3. Reviewed by Attorneys. Each Restricted Person represents and warrants to
Administrative Agent and each Holder that it (a) understands fully the terms of this Amendment and
the consequences of the execution and delivery of this Amendment, (b) has been afforded an
opportunity to have this Amendment reviewed by, and to discuss this Amendment and document executed
in connection herewith with, such attorneys and other persons as such Person may wish, and (c) has
entered into this Amendment and executed and delivered all documents in connection herewith of its
own free will and accord and without threat, duress or other coercion of any kind by any Person.
The parties hereto acknowledge and agree that neither this Amendment nor the other documents
executed pursuant hereto shall be construed more favorably in favor of one than the other based
upon which party drafted the same, it being acknowledged that all parties hereto contributed
substantially to the negotiation and preparation of this Amendment and the other documents executed
pursuant hereto or in connection herewith.



[First Amendment to

Note Purchase Agreement]





 


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Section 5.4. Survival of Agreements. All representations, warranties, covenants and
agreements of Company herein shall survive the execution and delivery of this Amendment and the
performance hereof, including without limitation the making or granting of the Loans, and shall
further survive until all of the Obligations are paid in full. All statements and agreements
contained in any certificate or instrument delivered by any Restricted Person hereunder or under
the Note Purchase Agreement to any Holder shall be deemed to constitute representations and
warranties by, and/or agreements and covenants of, Company under this Amendment and under the Note
Purchase Agreement.



Section 5.5. Note Documents. This Amendment is and the other Amendment Documents are
each a Note Document, and all provisions in the Note Purchase Agreement pertaining to Note
Documents apply hereto and thereto.



Section 5.6. Governing Law. Except to the extent that the law of another
jurisdiction is expressly elected in a Note Document, this Amendment and the other Amendment
Documents shall be governed by and construed in accordance with the internal laws of the State of
New York, without regard to principles of conflicts of laws. 



Section 5.7. Counterparts; Fax. This Amendment may be separately executed in
counterparts and by the different parties hereto in separate counterparts, each of which when so
executed shall be deemed to constitute one and the same Amendment. This Amendment and the other
Amendment Documents may be validly executed by facsimile or other electronic transmission.



This written Agreement and the other Note Documents represent the final agreement between
the parties and may not be contradicted by evidence of prior, contemporaneous, or subsequent oral
agreements of the parties.




There are no unwritten oral agreements between the parties.



[The remainder of this page has been intentionally left blank.]




[First Amendment to

Note Purchase Agreement]






 


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IN WITNESS WHEREOF, this Amendment is executed as of the date first above written.



	 	 	 	 	 
	 	COMPANY:


RIO VISTA PENNY LLC

 	 
	 	By:  	 	 
	 	 	Ian Bothwell 	 
	 	 	Manager 	 
	 



[Signature Page to First Amendment to

Note Purchase Agreement]





 


 









 







	 	 	 	 	 	 	 	 	 	 	 
	 	 	ADMINISTRATIVE AGENT:	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	TCW ASSET MANAGEMENT COMPANY,

Administrative Agent	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	By:	 	 	 	 	 	 	 	 
	 	 	 	 	 	 	 
	 

	 	 	 	Name:	 	 	 	 	 	 
	 

	 	 	 	Title:	 	 	 	 	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	By:	 	 	 	 	 	 	 	 
	 	 	 	 	 	 	 
	 

	 	 	 	Name:	 	 	 	 	 	 
	 

	 	 	 	Title:	 	 	 	 	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	HOLDERS:	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	TCW ENERGY FUND X – NL, L.P.,

a California limited partnership	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	By:	 	TCW (ENERGY X) LLC, its General Partner:	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	 	 	By:	 	TCW Asset Management Company,

its Managing Member	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 	 	 
	 

	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	 	 	Name:	 	 
	 

	 	 	 	 	 	 	 	Title:	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 	 	 
	 

	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	 	 	Name:	 	 
	 

	 	 	 	 	 	 	 	Title:	 	 






[Signature Page to First Amendment to

Note Purchase Agreement]





 


 









 







	 	 	 	 	 	 	 	 	 	 	 
	 	 	TCW ENERGY FUND XB – NL, L.P.,

a California limited partnership	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	By:	 	TCW (ENERGY X) LLC, its General Partner:	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	 	 	By:	 	TCW Asset Management Company,

its Managing Member	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 	 	 
	 

	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	 	 	Name:	 	 
	 

	 	 	 	 	 	 	 	Title:	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 	 	 
	 

	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	 	 	Name:	 	 
	 

	 	 	 	 	 	 	 	Title:	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	TCW ENERGY FUND XC – NL, L.P.,

a California limited partnership	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	By:	 	TCW (ENERGY X) LLC, its General Partner:	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	 	 	By:	 	TCW Asset Management Company,

its Managing Member	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 	 	 
	 

	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	 	 	Name:	 	 
	 

	 	 	 	 	 	 	 	Title:	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 	 	 
	 

	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	 	 	Name:	 	 
	 

	 	 	 	 	 	 	 	Title:	 	 






[Signature Page to First Amendment to

Note Purchase Agreement]






 


 









 







	 	 	 	 	 	 	 	 	 	 	 
	 	 	TCW ENERGY FUND XD – NL, L.P.,

a California limited partnership	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	By:	 	TCW (ENERGY X) LLC, its General Partner:	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	 	 	By:	 	TCW Asset Management Company,

its Managing Member	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 	 	 
	 

	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	 	 	Name:	 	 
	 

	 	 	 	 	 	 	 	Title:	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	By:	 	 	 	 
	 

	 	 	 	 	 	 	 	 	 	 
	 

	 	 	 	 	 	 	 	Name:	 	 
	 

	 	 	 	 	 	 	 	Title:	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 	 	TCW ASSET MANAGEMENT COMPANY, a California

corporation, as Investment Manager under the Amended 

and Restated Investment Management and Custody 

Agreement dated as of December 3, 2003 among Ensign

Peak Advisors, Inc., TCW Asset Management Company and

Trust Company of the West, a California trust

company, as Sub-Custodian	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	By:	 	 	 	 	 	 	 	 
	 	 	 	 	 	 	 
	 

	 	 	 	Name:	 	 	 	 	 	 
	 

	 	 	 	Title:	 	 	 	 	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	 

	 	By:	 	 	 	 	 	 	 	 
	 	 	 	 	 	 	 
	 

	 	 	 	Name:	 	 	 	 	 	 
	 

	 	 	 	Title:	 	 	 	 	 	 






[Signature Page to First Amendment to

Note Purchase Agreement]





 


 









 







	 	 	 	 	 
	 	TCW ASSET MANAGEMENT COMPANY, a California

corporation, as Investment Manager under the Amended

and Restated Investment Management and Custody

Agreement dated as of December 11, 2003 among Harry

L. Bradley, Jr. Partition Trust, Harry L. Bradley,

Jr. Trust, Jane Bradley Uihlien Pettit Partition

Trust, Jane Bradley Uihlien Trust, TCW Asset

Management Company and Trust Company of the West, a

California trust company, as Sub-Custodian

 	 
	 	By:  	 	 
	 	 	Name:  	 	 
	 	 	Title:  	 	 
	 	 	 
	 	By:  	
 	 
	 	 	Name:  	 	 
	 	 	Title:  	 	 
	 
	 	TCW ASSET MANAGEMENT COMPANY, a California

corporation, as Investment Manager under the Amended

and Restated Investment Management and Custody

Agreement dated as of March 18, 2004 among ING Life

Insurance and Annuity Company, TCW Asset Management

Company and Trust Company of the West, a California

trust company, as Sub-Custodian

 	 
	 	By:  	 	 
	 	 	Name:  	 	 
	 	 	Title:  	 	 
	 	 	 
	 	By:  	
 	 
	 	 	Name:  	 	 
	 	 	Title:  	 	 
	 



[Signature Page to First Amendment to

Note Purchase Agreement]





 


 









 







First Amendment




CONSENT AND REAFFIRMATION





Each of the undersigned hereby (i) consents to the provisions of this Amendment and the
transactions contemplated herein, (ii) ratifies and confirms the Management Services Agreement, the
Guaranty dated November 19, 2007, and the other Note Documents, in each case to which it is a
party, (iii) agrees that all of its respective obligations and covenants thereunder shall remain
unimpaired by the execution and delivery of this Amendment and the other Amendment Documents, and
(iv) agrees that the Management Services Agreement, such Guaranty, and such other Note Documents
shall remain in full force and effect.



	 	 	 	 	 
	 	RIO VISTA ECO LLC

 	 
	 	By:  	 	 
	 	 	Ian Bothwell 	 
	 	 	Manager 	 
	 
	 	RIO VISTA GO LLC

 	 
	 	By:  	 	 
	 	 	Ian Bothwell 	 
	 	 	Manager 	 
	 
	 	GO, LLC

 	 
	 	By:  	 	 
	 	 	Ian Bothwell 	 
	 	 	Manager 	 
	 
	 	MV PIPELINE COMPANY

 	 
	 	By:  	 	 
	 	 	Ian Bothwell 	 
	 	 	President 	 
	 



[Signature Page to First Amendment to

Note Purchase Agreement]





 


 









 







	 	 	 	 	 
	 	RIO VISTA OPERATING LLC

 	 
	 	By:  	 	 
	 	 	Ian Bothwell 	 
	 	 	Manager 	 
	 
	 	RIO VISTA ENERGY PARTNERS L.P.

 	 
	 	By:  	Rio Vista GP LLC, its general partner
 	 
	 	 	 
	 	By:  	
 	 
	 	 	Ian Bothwell 	 
	 	 	Manager 	 
	 



[Signature Page to First Amendment to

Note Purchase Agreement]





 


 









 







SCHEDULE 1




Rio Vista

Fixed price Sales Contracts




Counterparty: Clearwater Enterprises, L.L.C.




	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 	 
	 	 	 	 	 	 	 	 	 	 	Contract	 	 	Contract	 	 	 	 	 
	Confirmation	 	 	 	 	 	 	 	 	 	Quantity	 	 	Price	 	 	 	 	 
	Number	 	Begin	 	 	End	 	 	(mmbtu/mo)	 	 	($/mmbtu)	 	 	Pipeline	 	Delivery Point/Index Point
	28727
	 	 	4/1/2008	 	 	 	10/31/2008	 	 	 	30,000	 	 	 	6.35	 	 	Oneok Gas Transmission	 	MV/OGT (R900)
	31601
	 	 	11/1/2008	 	 	 	3/31/2009	 	 	 	30,000	 	 	 	8.61	 	 	Oneok Gas Transmission	 	MV/OGT (R900)
	31595 & 31956
	 	 	4/1/2008	 	 	 	10/31/2008	 	 	 	15,000	 	 	 	7.97	 	 	NA	 	Swap: Inside Ferc Centerpoint East
	31597 & 31958
	 	 	11/1/2008	 	 	 	3/31/2009	 	 	 	15,000	 	 	 	8.61	 	 	NA	 	Swap: Inside Ferc Centerpoint East






[Schedule I —  First Amendment to Note Purchase Agreement]




 


 









 







SCHEDULE 4




HOLDERS SCHEDULE




	 	 	 	 	 	 	 	 	 	 	 	 	 
	 	 	Allocation	 	 	 	 	 	 	Maximum	 
	Note Holder	 	%	 	 	Commitment	 	 	Credit Amount	 
	TCW Energy Fund X-NL,
L.P., a California
limited partnership
	 	 	23.03872	%	 	$	5,702,083.20	 	 	$	6,911,616	 
	TCW Energy Fund XB-NL,
L.P., a California
limited partnership
	 	 	28.62534	%	 	$	7,084,771.65	 	 	$	8,587,602	 
	TCW Energy Fund XC-NL,
L.P., a California
limited partnership
	 	 	9.48725	%	 	$	2,348,094.38	 	 	$	2,846,175	 
	TCW Energy Fund XD-NL,
L.P., a California
limited partnership
	 	 	21.12823	%	 	$	5,229,236.93	 	 	$	6,338,469	 
	Trust Company of the
West as Sub-Custodian
under the Amended and
Restated Investment
Management and Custody
Agreement dated as of
December 3, 2003 among
Ensign Peak Advisors,
Inc., TCW Asset
Management Company and
Trust Company of the
West
	 	 	6.81556	%	 	$	1,686,851.10	 	 	$	2,044,668	 
	ING Life Insurance and
Annuity Company
	 	 	6.81556	%	 	$	1,686,851.10	 	 	$	2,044,668	 
	Trust Company of the
West as Sub-Custodian
under the Amended and
Restated Investment
Management and Custody
Agreement dated as of
December 11, 2003 among
Harry L. Bradley, Jr.
Partition Trust, Harry
L. Bradley, Jr. Trust,
Jane Bradley Uihlien
Pettit Partition Trust,
Jane Bradley Uihlien
Trust, TCW Asset
Management Company and
Trust Company of the
West
	 	 	4.08934	%	 	$	1,012,111.64	 	 	$	1,226,802	 
	 
	 	 	 	 	 	 	 	 	 
	Total
	 	 	100.00000	%	 	$	24,750,000.00	 	 	$	30,000,000	 
	 
	 	 	 	 	 	 	 	 	 






[Schedule 4 — First Amendment to

Note Purchase Agreement]




 


 









 







SCHEDULE 6




APPROVED PLAN OF DEVELOPMENT




[Schedule 6 — First Amendment to

Note Purchase Agreement]





 


 









 







EXHIBIT A

TO

FIRST AMENDMENT TO NOTE PURCHASE AGREEMENT




CLOSING CERTIFICATE




CLOSING CERTIFICATE




September  _____, 2008





THE UNDERSIGNED HEREBY CERTIFIES AS FOLLOWS:



1. I am the sole Manager of Rio Vista Penny LLC, an Oklahoma limited liability company
(“Company”).



2. I have reviewed the terms of the Note Purchase Agreement dated as of November 19, 2007
among Company, TCW Asset Management Company, as Administrative Agent, and TCW Energy Fund X
Investors, as Holders party thereto (as amended, the “Note Purchase Agreement”; the terms defined
therein and not otherwise defined herein being used herein as therein defined), which is being
amended by the First Amendment to Note Purchase Agreement dated of even date herewith (the “First
Amendment” and the “Amendment Date”) by and among Company, Administrative Agent, and Holders. I
have also reviewed the Manager’s Certificate dated November 19, 2007 executed by the undersigned
and delivered pursuant to the Note Purchase Agreement (the “Original Certificate”).



3. In my opinion I have made, or have caused to be made under my supervision, such examination
or investigation as is necessary to enable me to express an informed opinion as to the matters
referred to herein.



4. Based upon my review and examination described in paragraph 3 above, I certify, on behalf
of Company, that as of the date hereof:




	 	a.	 	all representations and warranties made by any Person in any Note
Document are true in all respects on and as of the date hereof, except to the
extent that such representation or warranty was made as of a specific date or
updated, modified or supplemented as of a subsequent date with the consent of
Required Holders and Administrative Agent;
	 
	 	b.	 	each Restricted Person and Parent have performed and complied with all
agreements and conditions required in the Note Documents to be performed or
complied with prior to the date hereof;
	 
	 	c.	 	as of the Amendment Date, no event has occurred and is continuing or
would result from the consummation of the borrowing contemplated on the date hereof
that would constitute an Event of Default or a Default (other than the Designated
Defaults defined and described in the First Amendment, which are being waived
pursuant to the provisions of Section 2.8 of the First Amendment);





[Closing Certificate]




 


 









 








	 	d.	 	attached as Exhibit A to the Original Certificate is a true, correct
and complete copy of the Articles of Organization of Company as in effect on the
date hereof, certified by the Secretary of State of the State of Oklahoma;
	 
	 	e.	 	attached as Exhibit B to the Original Certificate is a true, correct
and complete copy of the Operating Agreement of Company as in effect on the date
hereof;
	 
	 	f.	 	attached as Exhibit D to the Original Certificate is a true, correct
and complete copy of certain resolutions duly adopted by unanimous written consent
of the sole Manager of Company in accordance with Company’s Articles of
Organization and Operating Agreement and none of such resolutions has been
rescinded, revoked, modified, or amended in any respect, and all of such
resolutions are in full force and effect on the date hereof;
	 
	 	g.	 	Paragraph 6 of the Original Certificate contains a list of certain duly
elected, qualified and acting officers of Company. Each such person holds on the
date hereof the office set forth opposite such officer’s name in such Paragraph 6,
and the signature appearing in such Paragraph 6 opposite such officer’s name is
such officer’s genuine signature. Each such officer is duly authorized to execute
and deliver Transaction Documents on behalf of Company;
	 
	 	h.	 	as of the Amendment Date no Restricted Person has any Deposit Account
that is not subject to a control agreement in form and substance satisfactory to
Administrative Agent as required by Section 7.17 of the Note Purchase Agreement.





[Remainder of page intentionally left blank. Signature page follows.]




[Closing Certificate]




 


 









 







IN WITNESS WHEREOF, this instrument is executed by the undersigned as of the date first
written above.



	 	 	 	 	 
	 	By:  	
 	 
	 	 	Ian Bothwell 	 
	 	 	Manager 	 
	 



[Closing Certificate]