**Exhibit** **10.19**




FEBRUARY
      2008 AMENDMENT AGREEMENT




THIS
      FEBRUARY 2008 AMENDMENT AGREEMENT (this “ **Amendment** ”)
      is
      made as of February 14, 2008, by and between SONTERRA RESOURCES, INC., a
      Delaware corporation (f/k/a River Capital Group, Inc., Ballistic Ventures,
      Inc.,
      a whOOdoo.com, Inc., Greystone Credit Inc. and Permastoprust International,
      Inc.), with principal offices located at 7 Reid Street, Suite 312, Hamilton
      Bermuda, HM11 prior to the Exchange Closing (as defined in the Exchange
      Agreement) and to be located at 300 East Sonterra Boulevard, San Antonio, Texas,
      78258 as of and after the Exchange Closing (“ **RCGI** ”),
      and
      THE LONGVIEW FUND, L.P., a California limited partnership with its principal
      offices located at 600 Montgomery Street, 44th Floor, San Francisco, CA 94111
      and other offices in Connecticut and New York (“ **Longview** ”).
      Capitalized terms not otherwise defined herein shall have the meanings given
      to
      them in the Exchange Agreement (as defined below).




**WHEREAS:**




A.  RCGI
      and
      Longview entered into that certain Securities Exchange and Additional Purchase
      Agreement, dated as of August 3, 2007 (as amended, the “ **Exchange
      Agreement** ”).




B.  Contemporaneously
      with the execution and delivery of the Exchange Agreement, Longview purchased the
      Sonterra Equity Note from Sonterra Oil
&
      Gas, Inc., a Delaware Corporation (f/k/a Sonterra Resources, Inc.)
      (“ **Sonterra** ”).




C.  At
      the
      Flash Acquisition Closing, Longview purchased the Sonterra Non-Equity Note
      from
      Sonterra.




D.  The
      Exchange Agreement provides that, at the Exchange Closing (which is to occur
      on
      the date hereof) among other things Longview will exchange with RCGI (i) the
      Sonterra Equity Note and the New Sonterra Common Shares for the New RCGI Common
      Shares, and (ii) the Sonterra Non-Equity Note for the Initial RCGI Note in
      an
      initial principal amount equal to the outstanding principal amount of the
      Sonterra Non-Equity Note.







E.  The
      Exchange Agreement further provides that, at the Exchange Closing, RCGI shall
      pay to Longview the Exchange Settlement Amount, which equals the sum of (I)
      Longview’s legal, due diligence and other expenses incurred in connection with
      the Exchange Closing and all other expenses relating to negotiating and
      preparing the Transaction Documents and consummating the transactions
      contemplated thereby, plus (II) all interest under the Sonterra Equity Note
      and
      under the Sonterra Non-Equity Note that was accrued and unpaid immediately
      prior
      to the Exchange Closing.




F.  In
      light
      of the accrued and unpaid interest owing under the Sonterra Equity Note and
      under the Sonterra Non-Equity Note, RCGI and Longview hereby deem it advisable
      and in the best interests of the undersigned to amend the Exchange Agreement
      and
      the terms of the Initial RCGI Note as provided herein.




NOW,
      THEREFORE, in consideration of the agreements, provisions and covenants
      contained herein and for other good and valuable consideration, the receipt
      and
      sufficiency of which are hereby acknowledged, each of the undersigned agrees
      as
      follows:




1.  Amendment
      of the Initial RCGI Note To Include Interest Since January 3 .




a.  Each
      of
      RCGI and Longview acknowledges and agrees that the Interest (as defined in
      the
      Sonterra Non-Equity Note) that is accrued and unpaid immediately prior to the
      date hereof (i.e., Interest accrued from and including January 3, 2008 through
      and including February 14, 2008) is $30,466.62.




b.  RCGI
      and
      Longview agree that the Initial RCGI Note shall be in the form of the Initial
      RCGI Note attached as Exhibit A to the Exchange Agreement, except that Sections
      2(n) and 2(o) of the Initial RCGI Note shall state in their entirety as follows
      (i.e., Sections 2(n) and 2(o) of the form of Initial RCGI Note attached as
      Exhibit A to the Employment Agreement are hereby amended and restated to read
      in
      their entirety as follows):




(o)
            “**Interest
                Amount**”
                means as of any date, with respect to any Principal, all accrued
                and
                unpaid Interest (including any Interest at the Default Rate) on such
                Principal through and including such date;provided,
                however, that,
                “Interest Amount” shall mean, as of any date from and including the
                Issuance Date until the entire Additional Interest Amount has been
                paid in
                full pursuant to this Note, with respect to any Principal, the sum
                of (i)
                all accrued and unpaid Interest (including any Interest at the Default
                Rate) on such Principal through and including such date plus (ii)
                any
                portion of the Additional Interest Amount that has not been paid
                to the
                Holder pursuant to this Note; and for purposes of this definition**“Additional
                Interest Amount**”
                means $30,466.62.




(p)
            “**Interest
                Payment Date**”
                means the first Business Day of each calendar quarter, beginning
                with the
                calendar quarter that commences on April 1, 2008, through and including
                the last calendar quarter that commences prior to the Maturity
                Date.




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2.  Amendment
      of the Exchange Agreement - Exchange of Accrued Interest on Sonterra Equity
      Note .




a.  Each
      of
      RCGI and Longview acknowledges and agrees that (i) as of February 13, 2008,
      the
      principal owing under the Sonterra Equity Note is $5,990,010, and (ii) the
      Interest (as defined in the Sonterra Equity Note) that is accrued and unpaid
      immediately prior to the date hereof (i.e., Interest accrued from and including
      January 3, 2008 through and including February 14, 2008) is
      $91,247.68.




b.  RCGI
      and
      Longview agree to amend, and hereby amend and restate in its entirety Section
      1(a)(i) of the Exchange Agreement, effective immediately prior to the Exchange
      Closing, as follows:




Subject
      to the satisfaction (or waiver) of the conditions set forth in Sections 6(a)
      and
      7(a) below, on the Exchange Closing Date, (A) RCGI shall issue to Buyer, and
      Buyer agrees to acquire from RCGI, the New RCGI Common Shares in exchange for
      Buyer’s assignment to RCGI of the Sonterra Equity Note (including all principal
      thereof and accrued and unpaid interest thereon) and the New Sonterra Common
      Shares (i.e., so that after such transactions, RCGI holds all of the New
      Sonterra Common Shares and the Sonterra Equity Note and Buyer holds the New
      RCGI
      Common Shares), (B) RCGI shall issue to Buyer, and Buyer agrees to acquire
      from
      RCGI, the RCGI Warrant in exchange for Buyer’s assignment to RCGI of the
      Sonterra Warrant (i.e., so that after such transactions, RCGI holds the Sonterra
      Warrant and Buyer holds the RCGI Warrant), (C) RCGI shall issue to Buyer, and
      Buyer agrees to acquire from RCGI, the Initial RCGI Note in exchange for Buyer’s
      assignment to RCGI of the Sonterra Non-Equity Note (i.e., so that after such
      exchange RCGI holds the Sonterra Non-Equity Note and Buyer holds the Initial
      RCGI Note), and (D) RCGI shall pay to Buyer an amount (the “ **Exchange
      Settlement Amount** ”)
      equal
      to all fees and other amounts to be paid to Buyer as set forth in Section 4(i).
      The completion of the exchanges provided for in this Section 1(a) shall effect
      the cancellation of the Sonterra Equity Note (including the termination of
      any
      obligations with respect to payment of any accrued and unpaid interest thereon),
      the Sonterra Warrants and the Sonterra Non-Equity Note (including the
      termination of any obligations with respect to payment of any accrued and unpaid
      interest thereon), and RCGI shall stamp “CANCELLED” on each of the foregoing and
      return each to Sonterra.




c.  As
      amended hereby, the Exchange Agreement remains in full force and
      effect.




3.  Obligations
      to Directors and Others .
      Amounts
      owing as of the Exchange Closing Date (as defined in the Exchange Agreement)
      to
      directors and former directors of RCGI or their affiliated entities, for
      services provided by them prior to the Exchange Closing, shall be paid to them
      by RCGI following the receipt by RCGI of the proceeds of any equity or debt
      financing consummated by RCGI, its affiliates or subsidiaries, after the
      Exchange Closing, and shall be paid within 2 business days of such receipt.
      In
      no event shall such payments be made later than 60 days following the Exchange
      Closing Date.




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4.  Avoidance
      of Doubt .
      The
      undersigned hereby agree, for the avoidance of doubt, that (a) this Amendment
      shall be a Transaction Document, (b) any references to the Exchange Agreement
      in
      any of the Transaction Documents shall mean the Exchange Agreement, as, and
      to
      the extent, amended by this Amendment, and (c) any references to the Initial
      RCGI Note in any of the Transaction Documents shall mean the Initial RCGI Note,
      in a form reflecting the terms of this Amendment.




5.  Reservation
      of Rights .
      RCGI
      acknowledges and agrees that the execution and delivery of this Amendment by
      Longview (a) shall not waive any breach, default, or event of default by them,
      respectively, that may be continuing under any of the Transaction Documents
      or
      any other documents, (b) shall not waive any of Longview’s rights or remedies
      arising from any such breach, default or event of default or otherwise available
      under any Transaction Document or at law, and Longview expressly reserves all
      such rights and remedies, and (c) shall not constitute a course of conduct
      or
      dealing among any of the undersigned.




6.  Successors
      and Assigns .
      This
      Amendment shall be binding upon and shall inure to the benefit of the parties
      hereto and their respective successors and permitted assigns. The successors
      and
      assigns of such entities shall include their respective receivers, trustees
      or
      debtors-in-possession.




7.  Further
      Assurances .
      RCGI
      and Longview each hereby agrees from time to time, as and when requested by
      Longview, to execute and deliver or cause to be executed and delivered, all
      such
      documents, instruments and agreements, including secretary’s certificates, stock
      powers and irrevocable transfer agent instructions, and to take or cause to
      be
      taken such further or other action, as Longview may reasonably deem necessary
      or
      desirable in order to carry out the intent and purposes of this Amendment,
      the
      Exchange Agreement (as amended hereby) and any other Transaction
      Documents.




8.  Rules
      of Construction .
      All
      words in the singular or plural include the singular and plural and pronouns
      stated in either the masculine, the feminine or neuter gender shall include
      the
      masculine, feminine and neuter, and the use of the word “including” in this
      Amendment shall be by way of example rather than limitation.




9.  Governing
      Law; Jurisdiction; Jury Trial .
      All
      questions concerning the construction, validity, enforcement and interpretation
      of this Amendment shall be governed by the internal laws of the State of New
      York, without giving effect to any choice of law or conflict of law provision
      or
      rule (whether of the State of New York or any other jurisdiction) that would
      cause the application of the laws of any jurisdiction other than the State
      of
      New York. Each party hereby irrevocably submits to the exclusive jurisdiction
      of
      the state and federal courts sitting in the City of New York, borough of
      Manhattan, for the adjudication of any dispute hereunder or in connection
      herewith or with any transaction contemplated hereby or discussed herein, and
      hereby irrevocably waives, and agrees not to assert in any suit, action or
      proceeding, any claim that it is not personally subject to the jurisdiction
      of
      any such court, that such suit, action or proceeding is brought in an
      inconvenient forum or that the venue of such suit, action or proceeding is
      improper. Each party hereby irrevocably waives personal service of process
      and
      consents to process being served in any such suit, action or proceeding by
      mailing a copy thereof by registered or certified mail, return receipt
      requested, or by deposit with a nationally recognized overnight delivery
      service, to such party at the address for such notices to it under this
      Amendment and agrees that such service shall constitute good and sufficient
      service of process and notice thereof. Nothing contained herein shall be deemed
      to limit in any way any right to serve process in any manner permitted by law.
      EACH PARTY HEREBY IRREVOCABLY WAIVES ANY RIGHT IT MAY HAVE, AND AGREES NOT
      TO
      REQUEST, A JURY TRIAL FOR THE ADJUDICATION OF ANY DISPUTE HEREUNDER OR IN
      CONNECTION HEREWITH OR ARISING OUT OF THIS AMENDMENT OR ANY TRANSACTION
      CONTEMPLATED HEREBY.




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10.  Counterparts .
      This
      Amendment may be executed in two or more identical counterparts, all of which
      shall be considered one and the same agreement and shall become effective when
      counterparts have been signed by each party and delivered to each other party. In
      the
      event that any signature to this Amendment or any amendment hereto is delivered
      by facsimile transmission or by e-mail delivery of a “.pdf” format data file,
      such signature shall create a valid and binding obligation of the party
      executing (or on whose behalf such signature is executed) with the same force
      and effect as if such facsimile or “.pdf” signature page were an original
      thereof. No party hereto shall raise the use of a facsimile machine or e-mail
      delivery of a “.pdf” format data file to deliver a signature to this Amendment
      or any amendment hereto or the fact that such signature was transmitted or
      communicated through the use of a facsimile machine or e-mail delivery of a
      “.pdf” format data file as a defense to the formation or enforceability of a
      contract, and each party hereto forever waives any such defense.




11.  Section
      Headings .
      The
      section headings herein are for convenience of reference only, and shall not
      affect in any way the interpretation of any of the provisions
      hereof.




12.  No
      Strict Construction .
      The
      language used in this Amendment will be deemed to be the language chosen by
      the
      parties hereto to express their mutual intent, and no rule of strict
      construction will be applied against any party.




13.  Merger .
      This
      Amendment, the Exchange Agreement (as amended hereby) and the other Transaction
      Documents represent the final agreement of each of the parties hereto with
      respect to the matters contained herein and may not be contradicted by evidence
      of prior or contemporaneous agreements, or prior or subsequent oral agreements,
      among any of the parties hereto. This Amendment may not be amended, supplemented
      or otherwise modified except in a writing executed by each of the
      undersigned.




14.  Exchange
      Closing Contingency .
      Notwithstanding anything to the contrary herein, if the Exchange Closing and
      the
      all of the transactions contemplated by the Exchange Agreement to occur in
      connection therewith do not occur on February 14, 2008, then this Amendment,
      and
      any and all sections hereof, shall be deemed ineffective and void ab initio
      and
      the actions, transactions and amendments to other documents pursuant hereto
      shall be deemed never to have occurred.




**[Remainder
      of page intentionally left blank; Signature page follows]**




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IN
      WITNESS WHEREOF, this Amendment has been duly executed and delivered by each
      of
      the undersigned as of the date first above written.




**SONTERRA
              RESOURCES, INC.**,
              a
              Delaware corporation****By:
            /s/ Howard
              TaylorName:
            Howard
              TaylorTitle:
            Chief Executive Officer**THE LONGVIEW FUND, L.P.**,
              a
              California limited partnership




By:
                Viking Asset Management, LLC
              Its:
                Investment Adviser




By:
            /s/ S.
              Michael RudolphName:
            S.
              Michael RudolphTitle:
            Chief Financial Officer







**[Signature
      Page to the February 2008 Amendment Agreement]**




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