EXHIBIT 10.26



                               PLEDGE AGREEMENT


      THIS  PLEDGE  AGREEMENT,  made  as  of  this 1st day of April, 2008 (this
"AGREEMENT"),  is  by  each of SOUTH TEXAS OIL COMPANY,  a  Nevada  corporation
("COMPANY"), and STO OPERATING  COMPANY,  a Texas corporation ("STO OPERATING";
STO Operating, together with Company are each  referred  to individually herein
as a "PLEDGOR" and collectively as the "PLEDGORS"), in favor  of  VIKING  ASSET
MANAGEMENT,  LLC,  a  California limited liability company., in its capacity as
collateral agent for the  Buyers  identified  on Schedule B attached hereto (in
such capacity, together with its successors and  assigns  in such capacity, the
"PLEDGEE"), as successor lienholder to certain of the Buyers under the Original
Security Agreements (as defined in the Security Agreement referred to below).

                                   WHEREAS:

      A.    WHEREAS,  pursuant  to  that  certain Loan Agreement  (as  amended,
restated, supplemented or otherwise modified  from  time  to time and in effect
immediately  prior to the effectiveness of the Purchase Agreement  (as  defined
below), the "ORIGINAL  LOAN AGREEMENT"), dated January 31, 2007 between Company
and The Longview Fund, L.P.,  a  California  limited  partnership ("LONGVIEW"),
Company initially had the right to borrow from Longview an aggregate amount not
to  exceed  $15,000,000,  which  obligation  was represented  by  that  certain
Revolving Credit Note (as amended, restated, supplemented or otherwise modified
from time to time and in effect immediately prior  to  the effectiveness of the
Purchase Agreement, the "REVOLVING NOTE"), dated January  31,  2007,  issued by
the  Company  in  favor  of  Longview  in  connection  with  the  Original Loan
Agreement;

      B.    WHEREAS,  Company  and  Longview  entered  into that certain  First
Amendment to Loan Agreement and Revolving Credit Note (the  "FIRST AMENDMENT"),
dated  as  of  September 25, 2007, pursuant to which (i) Company  and  Longview
agreed to amend  and restate the Original Loan Agreement and the Revolving Note
to increase the aggregate  amount  that  Company  was  entitled  to borrow from
Longview (subject to the terms and conditions of the Original Loan  Agreement),
and  the  principal  amount  of  the  Revolving  Note, to $30,000,000, and (ii)
Pledgors  agreed  to  enter  into,  as  applicable,  (a)   a  guaranty  of  all
obligations,  liabilities and indebtedness of Company under the  Original  Loan
Agreement  and the  Revolving  Note  (as  amended,  restated,  supplemented  or
otherwise modified  from  time  to  time,  the  "SUBSIDIARY  GUARANTY"  and the
guarantees  under  the  Subsidiary Guaranty, including any such guarantee added
after  the  date  hereof,  the  "GUARANTEES"),  and  (b)  security  and  pledge
agreements  and such other documents  and  instruments  as  were  necessary  to
provide Pledgee  with  a  valid, perfected, first priority security interest in
substantially all of the assets of each of the Pledgors;

      C.    WHEREAS,  Company   and   Buyers have  entered  into  that  certain
Securities  Purchase  Agreement  dated as  of  the  date  hereof  (as  amended,
restated, supplemented or otherwise  modified  from time to time, the "PURCHASE
AGREEMENT"), pursuant to which, among other things,  (i) Company and Buyers are
amending  and  restating  in  its  entirety the Original Loan  Agreement,  (ii)
Company is issuing to Buyers the Initial  Notes  (as  defined  in  the Purchase
Agreement)  in  replacement  of,  and  as  an amendment and restatement in  the
entirety of, the Revolving Note, and (iii) Company  may  from  time to time, in
accordance with the terms of the Purchase Agreement, issue Additional Notes (as
defined in the Purchase Agreement) to the Buyers;

      D.    WHEREAS, pursuant to an Amended and Restated Security  Agreement of
even date herewith, as may be further amended, restated, modified or supplement
and  in  effect from time to time (the "SECURITY AGREEMENT"), each Pledgor  has
granted to  Pledgee,  for  its  benefit  and the benefit of the Buyers, a first
priority  security interest in, lien upon and  pledge  of  its  rights  in  the
Collateral (as defined in the Security Agreement);

      E.    WHEREAS,  (i)  Company  legally  and  beneficially  owns all of the
issued  and  outstanding  shares  of Capital Stock (as defined in the  Purchase
Agreement) of each of STO Operating Company, a Texas corporation formerly known
as Leexus Operating Company ("STO OPERATING"),  Southern  Texas  Oil Company, a
Texas  corporation  ("SOUTHERN  TEXAS")  and  STO  Drilling  Company,  a  Texas
corporation  ("STO  DRILLING"), and (ii) STO Operating legally and beneficially
owns all of the issued  and  outstanding membership interests of STO Properties
LLC, a Texas limited liability  company  ("STO  PROPERTIES",  together with STO
Operating,  Southern  Texas  and  STO  Drilling  and each other corporation  or
limited  liability company, the stock or other equity  interests  of  which  is
owned or acquired by a Pledgor and described on an addendum hereto from time to
time executed  by  a  Pledgor in form and substance satisfactory to Pledgee, is
referred to herein as a  "PLEDGED  ENTITY"  and  collectively  as  the "PLEDGED
ENTITIES"); and

      F.    WHEREAS, to induce Buyers to enter into the Purchase Agreement  and
to  purchase  the Notes (as defined in the Purchase Agreement), and in order to
secure the payment  and  performance  by  each  Pledgor  of the Obligations (as
defined  in  the  Security  Agreement), each Pledgor has agreed  to  pledge  to
Pledgee  all  of  the Capital Stock,  membership  interests  and  other  equity
interests and securities  of  the  Pledged  Entities  now or hereafter owned or
acquired by a Pledgor, as collateral security for the Obligations.

      NOW, THEREFORE, in consideration of the premises  and  in order to induce
Buyers to purchase the Notes under the Purchase Agreement and  for  other  good
and  valuable  consideration,  the  receipt and sufficiency of which are hereby
acknowledged, each Pledgor hereby agrees with Pledgee as follows:

            1.    Defined Terms.  Unless otherwise defined herein, all
      capitalized terms used herein shall have the meanings given them in the
      Purchase Agreement.

            2.    Pledge.

                  (a)   Each Pledgor  hereby  pledges,  assigns,  hypothecates,
      transfers, delivers and grants to Pledgee, for the benefit of  itself and
      Buyers, a first lien on and first priority perfected security interest in
      (i)  all  of  the  Capital  Stock,  membership  interests or other equity
      interests of the Pledged Entities now owned or hereafter acquired by such
      Pledgor  (collectively,  the  "PLEDGED  SHARES", which  include,  without
      limitation, the owned shares described on  Exhibit  A  attached  hereto),
      (ii)  all other property hereafter delivered to, or in the possession  or
      in the  custody  of,  Pledgee,  in substitution for or in addition to the
      Pledged Shares, (iii) any other property  of  a  Pledgor, as described in
      Section 4 below or otherwise, now or hereafter delivered  to,  or  in the
      possession  or  custody  of  a  Pledgor,  and  (iv)  all  proceeds of the
      collateral  described in the preceding clauses (i), (ii) and  (iii)  (the
      collateral described  in clauses (i) through (iv) of this Section 2 being
      collectively referred to  as  the  "PLEDGED  COLLATERAL"),  as collateral
      security  for  the prompt and complete payment and performance  when  due
      (whether at the  stated  maturity,  by  acceleration or otherwise) of the
      Obligations.  All of the Pledged Shares now  owned by a Pledgor which are
      presently  represented  by  stock  certificates or  membership  interests
      certificates are listed on Exhibit A  hereto, which stock certificates or
      membership interest certificates, with undated stock powers duly executed
      in blank by the applicable Pledgor and  irrevocable  proxies,  are  being
      delivered  to  Pledgee  simultaneously  herewith.   Upon  the creation or
      acquisition of any new Pledged Shares, Pledgor shall execute  an Addendum
      in  the  form  of  Exhibit C attached hereto (a "PLEDGE ADDENDUM").   Any
      Pledged Collateral described  in  a  Pledge  Addendum executed by Pledgor
      shall  thereafter be deemed to be listed on Exhibit  A  hereto.   Pledgee
      shall maintain  possession  and  custody of the certificates representing
      the Pledged Shares and any additional Pledged Collateral.

                  (b)   Pledgor shall cause  each  Pledged  Share consisting of
      either (i) a membership interest in a Person that is a  limited liability
      company or (ii) a partnership interest in a Person that is  a partnership
      (if  any)  to  be  "securities" governed by Article 8 of the UCC  at  all
      times.  Pledgor shall  cause the applicable Persons to issue certificates
      evidencing such membership interests or partnership interests (if any) to
      Pledgor.  Pledgor shall not cause and shall not permit any Pledged Entity
      which is not a corporation to "opt-out" of Article 8 of the UCC (provided
      that STO Operating, as the  sole member of STO Properties, shall have ten
      (10) business days from the date  of  this  Agreement  to certificate the
      membership  interests  of  STO  Properties  and deliver same  to  Pledgee
      together with an assignment separate from certificate  duly  executed  in
      blank).   Pledgor shall not take, and shall not permit any Pledged Entity
      which is not  a  corporation  to  take,  any actions to cause the Capital
      Stock,  membership  interests, partnership interests  or  similar  equity
      interests  of  such  Pledged   Entity   to  cease  to  be  classified  as
      "securities" governed by Article 8 of the UCC.

            3.    Representations and Warranties of Pledgors. Each Pledgor
      represents and warrants to Pledgee, and covenants with Pledgee, that:

                  (a)   Exhibit A sets forth (i)  the  authorized Capital Stock
      or membership interests of each Pledged Entity, (ii) the number of shares
      of Capital Stock or membership interests of each Pledged  Entity that are
      issued and outstanding as of the date hereof, and (iii) the percentage of
      the  issued  and  outstanding  shares  of  Capital  Stock  or  membership
      interests of each Pledged Entity held by a Pledgor.  Each Pledgor  is the
      record and beneficial owner of, and has good and marketable title to, the
      Pledged Shares owned by it, and such shares are and will remain free  and
      clear  of  all  pledges, liens, security interests and other encumbrances
      and restrictions  whatsoever,  except  the  liens  and security interests
      created by this Agreement;

                  (b)   there  are no outstanding options,  warrants  or  other
      agreements with respect to the Pledged Shares or any of the other Pledged
      Collateral;

                  (c)   this  Agreement   is   the  legal,  valid  and  binding
      obligation  of  each  Pledgor,  enforceable  against   such   Pledgor  in
      accordance   with   its  terms,  except  and  to  the  extent  that  such
      enforceability  is  subject   to   applicable   bankruptcy,   insolvency,
      reorganization, fraudulent conveyance and moratorium laws and other  laws
      of   general  application  affecting  enforcement  of  creditors'  rights
      generally,  or  the  availability of equitable remedies, all of which are
      subject to the discretion  of  the  court  before  which an action may be
      brought;

                  (d)   the   Pledged  Shares  have  been  duly   and   validly
      authorized and issued, are fully paid and non-assessable, and the Pledged
      Shares listed on Exhibit  A  constitute all of the issued and outstanding
      Capital Stock of the Pledged Entities;

                  (e)   no consent, approval or authorization of or designation
      or filing with any governmental  or  regulatory  authority on the part of
      any  Pledgor  is  required  in  connection with the pledge  and  security
      interest granted under this Agreement;

                  (f)   the  execution,   delivery   and  performance  of  this
      Agreement  will  not  violate  any  provision of any  applicable  law  or
      regulation or of any order, judgment, writ, award or decree of any court,
      arbitrator or governmental authority,  domestic  or  foreign,  or  of the
      articles  of  incorporation,  bylaws  or any other similar organizational
      documents  of any Pledgor or any Pledged  Entity  or  of  any  securities
      issued  by any  Pledgor  or  any  Pledged  Entity  or  of  any  mortgage,
      indenture, lease, contract, or other agreement, instrument or undertaking
      to which  a Pledgor or any Pledged Entity is a party or which purports to
      be binding upon a Pledgor or any Pledged Entity or upon any of the assets
      of a Pledgor  or  any Pledged Entity, and will not result in the creation
      or imposition of any  lien, charge or encumbrance on or security interest
      in any of the assets of  a  Pledgor  or  any  Pledged  Entity,  except as
      otherwise contemplated by this Agreement;

                  (g)   the  pledge,  assignment  and  delivery  of the Pledged
      Shares  and  the  other  Pledged  Collateral  pursuant  to this Agreement
      creates  a  valid  first  lien  on and perfected first priority  security
      interest in such Pledged Shares and  Pledged  Collateral and the proceeds
      thereof in favor of Pledgee, subject to no prior  pledge, lien, mortgage,
      hypothecation, security interest, charge, option or  encumbrance  nor  to
      any  agreement purporting to grant to any third party a security interest
      in the  property  or assets of a Pledgor, which would include the Pledged
      Shares  or  any  other  Pledged  Collateral.   Until  this  Agreement  is
      terminated pursuant  to  Section  11  hereof,  each Pledgor covenants and
      agrees that it will defend, for the benefit of Pledgee,  Pledgee's right,
      title and security interest in and to the applicable Pledged  Shares, the
      other Pledged Collateral and the proceeds thereof against the claims  and
      demands of all other persons or entities; and

                  (h)   Neither  Pledgor nor any Pledged Entity (i) will become
      a person whose property or interests  in  property are blocked or subject
      to blocking pursuant to Section 1 of Executive  Order  13224 of September
      23, 2001 Blocking Property and Prohibiting Transactions  with Persons Who
      Commit,   Threaten   to   Commit  or  Support  Terrorism  (66  Fed.  Reg.
      49079(2001), (ii) will engage  in any dealings or transactions prohibited
      by Section 2 of such executive order,  or  (iii)  will otherwise become a
      person on the list of Specially Designated Nationals  and Blocked Persons
      or subject to the limitations or prohibitions under any  other  Office of
      Foreign Asset Control regulation or executive order.

            4.    Stock   Dividends,   Distributions,   Etc.   If,  while  this
      Agreement  is in effect, a Pledgor shall become entitled  to  receive  or
      shall receive  (i)  any stock certificate (including, without limitation,
      any certificate representing  a stock dividend or a stock distribution in
      connection with any reclassification,  increase  or reduction of capital,
      or   issued   in   connection   with   any   reorganization,  merger   or
      consolidation), or any options or rights, whether  as  an addition to, in
      substitution  for,  or  in  exchange  for  any of the Pledged  Shares  or
      otherwise,  each Pledgor agrees, in each case,  to  accept  the  same  as
      Pledgee's agent and to hold the same in trust for Pledgee, and to deliver
      the same promptly  (but  in any event within five days) to Pledgee in the
      exact form received, with  the endorsement of the applicable Pledgor when
      necessary  and/or  with appropriate  undated  assignments  separate  from
      certificates or stock  powers  duly  executed  in  blank,  to  be held by
      Pledgee  subject  to  the terms hereof, as additional collateral security
      for the Obligations.  The  applicable  Pledgor  shall promptly deliver to
      Pledgee  (i)  a  Pledge  Addendum with respect to such  additional  stock
      certificates,  and  (ii)  any   financing  statements  or  amendments  to
      financing  statements  as requested  by  Pledgee.   Each  Pledgor  hereby
      authorizes Pledgee to attach each such Pledge Addendum to this Agreement.
      In case any distribution of capital shall be made on or in respect of the
      Pledged Shares or any property  shall be distributed upon or with respect
      to   the   Pledged   Shares   pursuant   to   the   recapitalization   or
      reclassification of the capital of the issuer  thereof or pursuant to the
      reorganization thereof, the property so distributed shall be delivered to
      Pledgee  to  be held by it as additional Pledged Collateral.   Except  as
      provided in Section 5(b) below, all sums of money and property so paid or
      distributed in  respect  of  the  Pledged  Shares  which  are received by
      Pledgor shall, until paid or delivered to Pledgee, be held  by Pledgor in
      trust as additional Pledged Collateral.

            5.    Voting Rights; Dividends.

                  (a)   So  long  as  no  Event of Default (as defined  in  the
      Notes) has occurred and is continuing,  each  Pledgor  shall  be entitled
      (subject  to  the  other  provisions hereof, including without limitation
      Section 8 below) to exercise  its voting and other consensual rights with
      respect to the applicable Pledged  Shares  and  to otherwise exercise the
      incidents of ownership thereof in any manner not  inconsistent  with this
      Agreement  or the Purchase Agreement and the other Transaction Documents.
      Each Pledgor  hereby  grants  to  Pledgee  or its nominee, an irrevocable
      proxy to exercise all voting and corporate rights relating to the Pledged
      Shares in any instance, which proxy shall be effective, at the discretion
      of Pledgee, upon the occurrence and during the continuance of an Event of
      Default.  After the occurrence and during the  continuance of an Event of
      Default and upon request of Pledgee, each Pledgor  agrees  to  deliver to
      Pledgee  such further evidence of such irrevocable proxy or such  further
      irrevocable proxies to vote the Pledged Shares as Pledgee may request.

                  (b)   So  long as no Event of Default shall have occurred and
      be continuing, Pledgor  shall  be  entitled  to receive cash dividends or
      other distributions made in respect of the Pledged  Shares, to the extent
      permitted to be made pursuant to the terms of the Purchase  Agreement  or
      the Notes.  Upon the occurrence and during the continuance of an Event of
      Default,  in  the event that a Pledgor, as record and beneficial owner of
      certain Pledged Shares, shall have received or shall have become entitled
      to receive, any  cash  dividends  or  other distributions in the ordinary
      course,  such  Pledgor shall deliver to Pledgee,  and  Pledgee  shall  be
      entitled to receive and retain, for the benefit of Pledgee, all such cash
      or other distributions as additional security for the Obligations.

                  (c)   Subject  to any sale or other disposition by Pledgee of
      the  Pledged  Shares, any other  Pledged  Collateral  or  other  property
      pursuant to this  Agreement,  upon full payment in cash, satisfaction and
      termination  of  all  of the Obligations  and  the  termination  of  this
      Agreement  pursuant to Section  11  hereof  of  the  liens  and  security
      interests  hereby   granted,   the  Pledged  Shares,  the  other  Pledged
      Collateral and any other property  then  held  as  part  of  the  Pledged
      Collateral  in accordance with the provisions of this Agreement shall  be
      returned to the  applicable  Pledgor or to such other persons or entities
      as shall be legally entitled thereto.

                  (d)   Pledgor  shall   cause   all   Pledged   Shares  to  be
      certificated at all times while this Agreement is in effect.

            6.    Rights of Pledgee.  Pledgee shall not be liable  for  failure
      to collect or realize upon the Obligations or any collateral security  or
      guaranty therefor, or any part thereof, or for any delay in so doing, nor
      shall  Pledgee be under any obligation to take any action whatsoever with
      regard thereto.   Any  or  all  of  the  Pledged  Shares  held by Pledgee
      hereunder  may,  if  an  Event of Default has occurred and is continuing,
      without notice, be registered  in the name of Pledgee or its nominee, and
      Pledgee or its nominee may thereafter  without notice exercise all voting
      and corporate rights at any meeting with  respect  to  any Pledged Entity
      and exercise any and all rights of conversion, exchange,  subscription or
      any other rights, privileges or options pertaining to any of  the Pledged
      Shares  as  if  it  were  the  absolute owner thereof, including, without
      limitation,  the right to vote in  favor  of,  and  to  exchange  at  its
      discretion  any   and  all  of  the  Pledged  Shares  upon,  the  merger,
      consolidation, reorganization,  recapitalization  or  other  readjustment
      with  respect  to any Pledged Entity or upon the exercise by any  Pledged
      Entity, a Pledgor or Pledgee of any right, privilege or option pertaining
      to any of the Pledged  Shares,  and,  in connection therewith, to deposit
      and  deliver  any  and  all of the Pledged  Shares  with  any  committee,
      depository, transfer agent,  registrar  or  other  designated agency upon
      such  terms  and  conditions  as  Pledgee may reasonably  determine,  all
      without liability except to account  for  property  actually  received by
      Pledgee, but Pledgee shall have no duty to exercise any of the  aforesaid
      rights,  privileges  or  options  and  shall  not  be responsible for any
      failure to do so or delay in so doing.

            7.    Remedies.  Upon the occurrence and during  the continuance of
      an  Event  of  Default,  Pledgee may exercise in respect of  the  Pledged
      Collateral, in addition to  other rights and remedies provided for herein
      or otherwise available to it,  all  the  rights and remedies of a secured
      party under the Uniform Commercial Code ("UCC") in effect in the State of
      New  York  from  time to time, whether or not  the  UCC  applies  to  the
      affected Pledged Collateral  (or the Uniform Commercial Code as in effect
      in any other relevant jurisdiction).   Pledgee  also,  without  demand of
      performance or other demand, advertisement or notice of any kind  (except
      the  notice  specified below of time and place of public or private sale)
      to or upon any  Pledgor  or  any  other person or entity (all and each of
      which  demands,  advertisements  and/or   notices  are  hereby  expressly
      waived), may, upon the occurrence and during  the continuance of an Event
      of Default, forthwith collect, receive, appropriate  and realize upon the
      Pledged  Collateral, or any part thereof, and/or may forthwith  date  and
      otherwise fill in the blanks on any assignments separate from certificate
      or stock power  or  otherwise  sell, assign, give an option or options to
      purchase,  contract to sell or otherwise  dispose  of  and  deliver  said
      Pledged Collateral,  or  any part thereof, in one or more portions at one
      or more public or private  sales  or  dispositions,  at  any  exchange or
      broker's  board  or  at  any of Pledgee's offices or elsewhere upon  such
      terms and conditions as Pledgee  may deem advisable and at such prices as
      it may deem best, for any combination  of cash and/or securities or other
      property or on credit or for future delivery  without  assumption  of any
      credit  risk,  with  the  right  to Pledgee upon any such sale, public or
      private, to purchase the whole or  any part of said Pledged Collateral so
      sold,  free  of  any  right or equity of  redemption  in  the  applicable
      Pledgor, which right or  equity  is  hereby expressly waived or released.
      Pledgee shall apply the net proceeds of  any  such  collection, recovery,
      receipt, appropriation, realization, sale or disposition, after deducting
      all costs and expenses of every kind incurred therein  or  incidental  to
      the  safekeeping  of  any and all of the Pledged Collateral or in any way
      relating to the rights  of  Pledgee  hereunder, including attorneys' fees
      and legal expenses, first to the payment,  in  whole  or  in part, of the
      Obligations, in such order as Pledgee may elect.  Pledgors  shall  remain
      liable for any deficiency remaining unpaid after such application.   Only
      after  so  paying over such net proceeds and after the payment by Pledgee
      of any other  amount required by any provision of law, including, without
      limitation, Section 9-608 of the UCC, will Pledgee be required to account
      for the surplus,  if any, to the applicable Pledgor.  Each Pledgor agrees
      that Pledgee is not  required  to give more than ten (10) days' notice of
      the time and place of any public  sale  or  of  the  time  after  which a
      private sale or other intended disposition is to take place and that such
      notice is reasonable notification of such matters.  No notification needs
      to  be  given  to  a  Pledgor, if it has signed after default a statement
      renouncing or modifying  any  right  to  notification  of  sale  or other
      intended disposition.

            8.    No  Disposition, Etc.  Until the irrevocable payment in  full
      in cash of the Obligations,  each  Pledgor  agrees that it will not sell,
      assign, transfer, exchange, or otherwise dispose  of, or grant any option
      with respect to, the Pledged Shares or any other Pledged  Collateral, nor
      will  such  Pledgor  create,  incur or permit to exist any pledge,  lien,
      mortgage, hypothecation, security  interest,  charge, option or any other
      encumbrance with respect to any of the Pledged  Shares  or  to  any other
      Pledged  Collateral,  or  any  interest therein, or any proceeds thereof,
      except for the lien and security  interest provided for by this Agreement
      and the Security Agreement and Permitted Liens.

            9.    Sale of Pledged Shares.

                  (a)   Each Pledgor recognizes  that  Pledgee may be unable to
      effect  a  public sale or disposition (including without  limitation  any
      disposition  in  connection  with a merger of a Pledged Entity) of any or
      all the Pledged Shares by reason of certain prohibitions contained in the
      Securities Act of 1933, as amended (the "1933 ACT"), and applicable state
      securities laws, but may be compelled  to  resort  to one or more private
      sales  or dispositions thereof to a restricted group  of  purchasers  who
      will be  obliged to agree, among other things, to acquire such securities
      for their  own  account,  for  investment  and  not  with  a  view to the
      distribution  or  resale  thereof.  Each Pledgor acknowledges and  agrees
      that any such private sale  or disposition may result in prices and other
      terms (including the terms of  any  securities or other property received
      in connection therewith) less favorable  to  the seller than if such sale
      or  disposition  were a public sale or disposition  and,  notwithstanding
      such circumstances,  agrees  that  any  such  private sale or disposition
      shall  be  deemed  to  be reasonable and consummated  in  a  commercially
      reasonable manner.  Pledgee  shall be under no obligation to delay a sale
      or disposition of any of the Pledged  Shares in order to permit a Pledgor
      or a Pledged Entity to register such securities for public sale under the
      1933 Act, or under applicable state securities laws, even if a Pledgor or
      a Pledged Entity would agree to do so.

                  (b)   Each Pledgor further  agrees  to do or cause to be done
      all such other acts and things as may be necessary  to make such sales or
      dispositions of the Pledged Shares valid and binding  and  in  compliance
      with   any   and   all   applicable  laws,  regulations,  orders,  writs,
      injunctions, decrees or awards  of  any  and  all  courts, arbitrators or
      governmental instrumentalities, domestic or foreign,  having jurisdiction
      over  any  such  sales  or dispositions, all at the applicable  Pledgor's
      expense; provided that Pledgor  shall  not have an obligation to register
      the Pledged Shares as securities under the  1933  Act  or  the applicable
      state  securities  laws  solely  by  virtue  of this Section 9(b).   Each
      Pledgor further agrees that a breach of any of the covenants contained in
      Sections  4,  5(a), 5(b), 8, 9 and 24 will cause  irreparable  injury  to
      Pledgee and that Pledgee has no adequate remedy at law in respect of such
      breach and, as  a  consequence,  agrees,  without  limiting  the right of
      Pledgee  to seek and obtain specific performance of other obligations  of
      each Pledgor  contained  in  this Agreement, that each and every covenant
      referenced above shall be specifically  enforceable against each Pledgor,
      and each Pledgor hereby waives and agrees  not  to  assert  any  defenses
      against an action for specific performance of such covenants.

                  (c)   Each  Pledgor  further  agrees  to  indemnify  and hold
      harmless  the  Buyers,  Pledgee,  and  their  respective  successors  and
      assigns,  their  respective officers, directors, employees, attorneys and
      agents, and any person  or  entity  in  control  of any thereof, from and
      against  any  loss,  liability,  claim,  damage  and expense,  including,
      without   limitation,   legal  fees  and  expenses  (in  this   paragraph
      collectively called the "INDEMNIFIED  LIABILITIES"),  under  federal  and
      state  securities laws or otherwise insofar as such Indemnified Liability
      (i) arises out of or is based upon any untrue statement or alleged untrue
      statement  of  a  material  fact contained in any registration statement,
      prospectus or offering memorandum  or  in  any  preliminary prospectus or
      preliminary offering memorandum or in any amendment  or supplement to any
      thereof or in any other writing prepared in connection  with  the  offer,
      sale  or  resale  of  all or any portion of the Pledged Collateral unless
      such untrue statement of  material  fact  was  provided  by  Pledgee,  in
      writing,  specifically for inclusion therein, or (ii) arises out of or is
      based upon  any  omission or alleged omission to state therein a material
      fact required to be  stated  or  necessary to make the statements therein
      not misleading, such indemnification  to  remain  operative regardless of
      any  investigation  made  by  or  on behalf of Pledgee or  any  successor
      thereof,  or  any  person  or  entity in  control  of  any  thereof.   In
      connection with a public sale or other distribution, Pledgor will provide
      customary  indemnification  to any  underwriters,  their  successors  and
      assigns, officers and directors  and  each  person or entity who controls
      any such underwriter (within the meaning of the 1933 Act).  If and to the
      extent  that  the  foregoing  undertakings  in  this   paragraph  may  be
      unenforceable  for  any reason, each Pledgor agrees to make  the  maximum
      contribution to the payment  and  satisfaction of each of the Indemnified
      Liabilities which is permissible under  applicable  law.  The obligations
      of each Pledgor under this paragraph (c) shall survive any termination of
      this Agreement.

                  (d)   Each Pledgor further agrees to waive any and all rights
      of  subrogation  it may have against a Pledged Entity upon  the  sale  or
      disposition of all  or  any  portion of the Pledged Collateral by Pledgee
      pursuant to the terms of this Agreement.

            10.   No Waiver; Cumulative  Remedies.   Pledgee  shall  not by any
      act,  delay,  omission  or otherwise be deemed to have waived any of  its
      remedies hereunder, and no  waiver  by  Pledgee  shall be valid unless in
      writing and signed by Pledgee, and then only to the  extent  therein  set
      forth.   A  waiver by Pledgee of any right or remedy hereunder on any one
      occasion shall  not  be  construed  as a bar to any right or remedy which
      Pledgee  would  otherwise have on any further  occasion.   No  course  of
      dealing between a Pledgor and Pledgee and no failure to exercise, nor any
      delay in exercising  on  the part of Pledgee or the Buyers of, any right,
      power or privilege hereunder  or  under  the  other Transaction Documents
      shall impair such right or remedy or operate as  a  waiver  thereof;  nor
      shall  any  single  or  partial exercise of any right, power or privilege
      hereunder preclude any other  or further exercise thereof or the exercise
      of any other right, power or privilege.   The  rights and remedies herein
      provided are cumulative and may be exercised singly  or concurrently, and
      are not exclusive of any rights or remedies provided by  law  or  in  the
      Purchase Agreement.

            11.   Termination.   This  Agreement  and  the  liens  and security
      interests  granted  hereunder  shall terminate, and Pledgee, at Pledgors'
      sole cost and expense, shall return  the  Pledged Shares or other Pledged
      Collateral then held by Pledgee to the applicable  Pledgor,  at  the time
      the  Security  Agreement  and  all Liens granted thereunder terminate  in
      accordance with Section 4.12 of the Security Agreement.


            12.   Possession of Collateral.   Beyond the exercise of reasonable
      care to assure the safe custody of the Pledged  Shares  in  the  physical
      possession  of  Pledgee pursuant hereto, neither Pledgee, nor any nominee
      of Pledgee, shall  have  any duty or liability to collect any sums due in
      respect thereof or to protect, preserve or exercise any rights pertaining
      thereto (including any duty  to  ascertain or take action with respect to
      calls,  conversions,  exchanges, maturities,  tenders  or  other  matters
      relating to the Pledged  Collateral  and  any  duty to take any necessary
      steps to preserve rights against any parties with  respect to the Pledged
      Collateral), and shall be relieved of all responsibility  for the Pledged
      Collateral upon surrendering them to a Pledgor.  Each Pledgor assumes the
      responsibility  for  being  and keeping itself informed of the  financial
      condition of a Pledged Entity and of all other circumstances bearing upon
      the risk of non-payment of the  Obligations,  and  Pledgee  shall have no
      duty to advise any Pledgor of information known to Pledgee regarding such
      condition  or  any  such  circumstance.   Pledgee  shall have no duty  to
      inquire  into the powers of a Pledged Entity or its officers,  directors,
      managers, members, partners or agents thereof acting or purporting to act
      on its behalf.

            13.   Taxes  and  Expenses.   Each  Pledgor will upon demand pay to
      Pledgee, (a) any taxes (excluding income taxes,  franchise taxes or other
      taxes levied on gross earnings, profits or the like  of  Pledgee) payable
      or  ruled  payable by any federal or state authority in respect  of  this
      Agreement, together  with  interest  and  penalties,  if any, and (b) all
      expenses, including the fees and expenses of counsel for  Pledgee  and of
      any experts and agents that Pledgee may incur in connection with (i)  the
      administration of this Agreement, (ii) the custody or preservation of, or
      the  sale  of,  collection  from,  or  other realization upon, any of the
      Pledged  Collateral, (iii) the exercise or  enforcement  of  any  of  the
      rights of  Pledgee hereunder, or (iv) the failure of a Pledgor to perform
      or observe any of the provisions hereof.

            14.   Pledgee  Appointed  Attorney-In-Fact.   Each  Pledgor  hereby
      irrevocably  appoints  Pledgee  as  such Pledgor's attorney-in-fact, with
      full authority in the place and stead  of such Pledgor and in the name of
      such Pledgor or otherwise, from time to  time in Pledgee's discretion, to
      take  any  action  and  to  execute  any instrument  that  Pledgee  deems
      reasonably  necessary or advisable to accomplish  the  purposes  of  this
      Agreement, including  without  limitation to receive, endorse and collect
      all instruments made payable to  such  Pledgor representing any dividend,
      interest  payment  or  other  distribution  in  respect  of  the  Pledged
      Collateral or any part thereof and to give full  discharge  for the same,
      when  and  to the extent permitted by this Agreement; provided  that  the
      power of attorney  granted  hereunder  shall only be exercised by Pledgee
      after the occurrence and during the continuance of an Event of Default.

            15.   Governing  Law;  Jurisdiction;  Jury  Trial.   All  questions
      concerning the construction, validity,  enforcement and interpretation of
      this Agreement 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 non-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  to  such  party  at  the
      address  for such notices to it under this Agreement 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.   The
      Parties acknowledge that each  of  the  Buyers  has  executed each of the
      Transaction Documents to be executed by it in the State  of  New York and
      will  have  made the payment of the Purchase Price from its bank  account
      located in the  State  of  New  York.  Notwithstanding the foregoing, the
      Pledgee may enforce its rights and  remedies  in  any  other jurisdiction
      applicable  to  the  Pledged  Collateral.  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 AGREEMENT OR ANY TRANSACTION CONTEMPLATED HEREBY.

            16.   Counterparts.  This Agreement may be  executed in two or more
      identical counterparts, all of which shall be considered one and the same
      agreement  and which shall become effective when counterparts  have  been
      signed by each party and delivered to the other party; provided, however,
      that a facsimile,  pdf  or  similar  electronically transmitted signature
      shall be considered due execution and shall be binding upon the signatory
      thereto  with the same force and effect  as  if  the  signature  were  an
      original, not a facsimile signature.

            17.   Headings.  The headings of this Agreement are for convenience
      of reference  and  shall  not form part of, nor affect the interpretation
      of, this Agreement.

            18.   Severability.   If  any  provision of this Agreement shall be
      invalid  or  unenforceable  in  any  jurisdiction,   such  invalidity  or
      unenforceability shall not affect the validity or enforceability  of  the
      remainder  of  this  Agreement  in  that  jurisdiction or the validity or
      enforceability  of  any  provision  of  this  Agreement   in   any  other
      jurisdiction.

            19.   Entire Agreement; Amendments.  This Agreement supersedes  all
      other prior oral or written agreements between each Pledgor, Pledgee, the
      Buyers  and  their  affiliates  and  persons  acting on their behalf with
      respect  to  the  matters discussed herein, and this  Agreement  and  the
      Transaction Documents  and  instruments  referenced  herein  and  therein
      contain  the  entire  understanding  of  the  parties with respect to the
      matters covered herein and therein.

            20.   Notices.  All notices, approvals, requests, demands and other
      communications hereunder shall be delivered or  made  in  the  manner set
      forth  in,  and  shall be effective in accordance with the terms of,  the
      Purchase Agreement.

            21.   Successors and Assigns.  This Agreement shall be binding upon
      and inure to the benefit  of  the parties and their respective successors
      and assigns, including any purchasers  of  the  Notes.   No Pledgor shall
      assign this Agreement or any rights or obligations hereunder  without the
      prior  written  consent  of  Pledgee.   Pledgee  may  assign  its  rights
      hereunder  without  the  consent  of  any  Pledgor,  in  which event such
      assignee  shall  be deemed to be Pledgee hereunder with respect  to  such
      assigned rights.

            22.   No Third Party Beneficiaries.  This Agreement is intended for
      the  benefit  of  the  parties  hereto  and  their  respective  permitted
      successors and permitted  assigns, and is not for the benefit of, nor may
      any provision hereof be enforced by, any other person or entity.

            23.   Survival.  All  representations,  warranties,  covenants  and
      agreements  of  each  Pledgor shall survive the execution and delivery of
      this Agreement.

            24.   Further Assurances.  Each Pledgor agrees that at any time and
      from time to time upon  the written request of Pledgee, each Pledgor will
      execute  and deliver all assignments  separate  from  certificate,  stock
      powers, financing  statements  and  such  further  documents  and do such
      further acts and things as Pledgee may reasonably request consistent with
      the  provisions  hereof  in order to carry out the intent and purpose  of
      this  Agreement and the consummation  of  the  transactions  contemplated
      hereby.

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

            26.   Pledgee  Authorized.   Each Pledgor hereby authorizes Pledgee
      to file one or more financing or continuation  statements  and amendments
      thereto  (or  similar  documents  required  by any laws of any applicable
      jurisdiction) relating to all or any part of  the Pledged Shares or other
      Pledged Collateral without the signature of the applicable Pledgor.

            27.   Pledgee Acknowledgment.Pledgor  acknowledges  receipt  of  an
      executed copy of this Agreement.  The Pledgor waives the right to receive
      any amount that it may now or hereafter be entitled  to  receive (whether
      by way of damages, fine, penalty, or otherwise) by reason  of the failure
      of  the  Pledgee  to  deliver  to  the  Pledgor  a  copy of any financing
      statement  or  any  statement  issued  by  any  registry  that   confirms
      registration of a financing statement relating to this Agreement.

            28.   Amendment and Restatement.     This Agreement, taken together
      with  the  Security  Agreement  dated  as  of the date hereof executed by
      Company, STO Operating, Southern Texas, STO  Drilling and STO Properties,
      amends and restates the Original Security Agreements  (as  defined in the
      Security  Agreement)  in  their  entirety,  and  shall  not be deemed  to
      constitute a novation of the Original Security Agreements  (as defined in
      the  Security  Agreement)  or any obligations of any "Debtor" thereunder.
      Each Pledgor acknowledges, ratifies,  confirms and reaffirms the grant of
      Liens  and  security  interests  and  the pledges  of  Capital  Stock  or
      membership   interests  granted  pursuant  to   the   Original   Security
      Agreements, and each Pledgor further acknowledges and agrees that (i) all
      of such Liens and security interests are intended and shall be deemed and
      construed to secure,  to  the  fullest  extent  set  forth  therein,  all
      currently existing and hereafter arising Obligations and (ii) all of such
      Liens  and  security  interests  shall continue hereunder in favor of the
      Pledgee uninterrupted from the date of the original grant thereof.


                           [SIGNATURE PAGE FOLLOWS]







<PAGE>

      IN WITNESS WHEREOF, the parties hereto  have caused this Pledge Agreement
to be duly executed and delivered by their duly authorized officers on the date
first above written.


                                    SOUTH TEXAS OIL COMPANY,
      a Nevada corporation, as a Pledgor

                                    By:________________________________
                                    Name: _____________________________
                                    Title:_______________________________


                                    STO OPERATING COMPANY,
                                    a Texas corporation, as a Pledgor

                                    By:________________________________
                                    Name:_____________________________
                                    Title:_______________________________



                                    VIKING ASSET MANAGEMENT, LLC, a California
                                    limited liability company, in its capacity
                                    as collateral agent for the Buyers

                                    By:________________________________
                                    Name: _____________________________
                                    Title:_______________________________

60626439

Pledge

<PAGE>

                                ACKNOWLEDGEMENT

      The  undersigned  hereby  (i)  acknowledges receipt  of  a  copy  of  the
foregoing Pledge Agreement, (ii) waives  any  rights or requirement at any time
hereafter to receive a copy of such Pledge Agreement  in  connection  with  the
registration  of any Pledged Shares (as defined therein) in the name of Pledgee
or its nominee  or  the  exercise  of voting rights by Pledgee and (iii) agrees
promptly to note on its books and records the grant of the security interest in
the stock of the undersigned as provided in such Pledge Agreement.

Dated:  April 1, 2008


                                    STO OPERATING COMPANY,
                                    a Texas corporation


                                    By:
                                    Name: _________________________
                                    Title:


                                    STO DRILLING COMPANY,
                                    a Texas corporation


                                    By:
                                    Name: _________________________
                                    Title:


                                    STO PROPERTIES LLC,
                                    a Texas limited liability company


                                    By:
                                    Name: _________________________
                                    Title:

                                    SOUTHERN TEXAS OIL COMPANY,
                                    a Texas corporation


                                    By:
                                    Name: _________________________
                                    Title:

<PAGE>
                                   EXHIBIT A
                              to Pledge Agreement

 DESCRIPTION OF CAPITAL STOCK OR MEMBERSHIP INTERESTS OF PLEDGED ENTITIES HELD
                          BY SOUTH TEXAS OIL COMPANY


<TABLE>
<CAPTION>

<S>			<C>			<C>

          Issuer           Owner Class of Stock orAuthorized No. of   Stock       No. of Shares    Issued and  Percentage of
                                    Membership         Shares      Certificate   Represented by   Outstanding Shares Held by
                                     Interests                         No.         Certificate       Shares       Pledgor

STO Operating Company, a  South  Common           50,000,000            #1     1,000,000          1,000,000
Texas corporation         Texas                                                                                    100%
                          Oil
                          Company
STO Drilling Company, a   South  Common           50,000,000            #1     1,000,000          1,000,000
Texas corporation         Texas                                                                                    100%
                          Oil
                          Company
Southern Texas Oil        South  Common           50,000,000            #2     1,000,000          1,000,000
Company, a Texas          Texas                                                                                    100%
corporation               Oil
                          Company
</TABLE>



 DESCRIPTION OF CAPITAL STOCK OR MEMBERSHIP INTERESTS OF PLEDGED ENTITIES HELD
                           BY STO OPERATING COMPANY

<TABLE>
<CAPTION>

<S>				<C>			<C>

          Issuer            Owner    Class of  Authorized No. of   Stock    No. of Shares Issued and  Percentage of Shares
                                     Stock or       Shares      Certificate  Represented Outstanding  or Interests Held by
                                    Membership                      No.          by         Shares          Pledgor
                                     Interests                               Certificate

STO Properties LLC, a     STO       Sole              n/a            #1          n/a         n/a              100%
Texas limited liability   Operating membership
company                   Company   interest


</TABLE>






<PAGE>
                                   EXHIBIT B
                              to Pledge Agreement

<TABLE>
<CAPTION>

        BUYER'S NAME                             BUYER'S ADDRESS
                                              AND FACSIMILE NUMBER
<S>                           <C>


      The Longview Fund, L.P.      600 Montgomery Street, 44th Floor, San Francisco,
                                   CA  94111

      Longview Marquis Master      600 Montgomery Street, 44th Floor, San Francisco,
      Fund, L.P.                   CA  94111

</TABLE>

<PAGE>
                                   EXHIBIT C
                              to Pledge Agreement

                         ADDENDUM TO PLEDGE AGREEMENT

The undersigned, being the Pledgor pursuant  to  that  certain Pledge Agreement
dated  as  of  April 1, 2007 (as amended, restated, supplemented  or  otherwise
modified from  time  to  time, the "PLEDGE AGREEMENT") in favor of Viking Asset
Management, LLC, a California  limited  liability  company, as collateral agent
("PLEDGEE"), by executing this Addendum, hereby acknowledges  that  Pledgor has
acquired and legally and beneficially owns all of the issued and outstanding  [
shares  of  Capital  Stock  ]  of  [__________________, a _______ corporation ]
("COMPANY")  described  below  (the  "SHARES").    Pledgor  hereby  agrees  and
acknowledges that the Shares shall be deemed Pledged  Shares  pursuant  to  the
Pledge  Agreement.   Pledgor hereby represents and warrants to Pledgee that (i)
all of the [ Capital Stock  ]  of the Company now owned by Pledgor is presently
represented by the certificates  listed below, which certificates, with undated
assignments separate from certificate or stock powers duly executed in blank by
Pledgor, are being delivered to Pledgee,  simultaneously herewith (or have been
previously  delivered  to  Pledgee),  and (ii)  after  giving  effect  to  this
addendum, the representations and warranties  set  forth  in  Section  3 of the
Pledge Agreement are true, complete and correct as of the date hereof.

                                PLEDGED SHARES

                                                  No. of Shares
  Name of                                         Represented by
the CompanyClass of Equity InterestCertificate No. Certificate




      IN WITNESS WHEREOF, Pledgor has executed this Addendum this _____ day of
______.

                                    PLEDGOR:

                                    ________________________, A
                                    _____________________

                                    By:________________________________
                                    Name:  ____________________________
                                    Title: ____________________________