DEPOSIT ACCOUNT CONTROL AGREEMENT

       THIS DEPOSIT ACCOUNT CONTROL AGREEMENT (this "Agreement") is entered
into as of April ____, 2008, by and among the following parties:

PARTIES:
VIKING ASSET MANAGEMENT, LLC, a California limited liability company
("Creditor")
SOUTH TEXAS OIL CO., a Nevada corporation ("Customer")
WELLS FARGO BANK, NATIONAL ASSOCIATION ("Depository")


BACKGROUND:

       Customer has granted to Creditor a security interest in a deposit
account maintained by Customer with Depository and in all funds now in, or
hereafter deposited into, that account, including any interest earned thereon.
The parties are entering into this Agreement to perfect Creditor's security
interest in that account.

       NOW, THEREFORE, in consideration of their mutual covenants and promises,
the parties agree as follows:

AGREEMENT:

       1.    The Account. Depository represents and warrants to Creditor that:

       (a)   Customer maintains deposit account number 1001-421583 with
Depository (said account and, if it is a certificate of deposit or other time
deposit, any renewal thereof shall be referred to as the "Account"). The
Account is a demand deposit account.

       (b)   As of the date of this Agreement Depository does not know of any
claim to or interest in the Account, except for claims and interests of the
parties hereto.

       2.    Control of Account by Creditor; Customer's Rights in Account.

       (a)   Depository will comply with instructions ("Orders") originated by
Creditor for the disposition of funds in the Account without further consent
from Customer and without regard to any inconsistent or conflicting Orders
given to Depository by Customer. Depository shall have a reasonable period of
time to comply with any Order.

       (b)   The provisions of the paragraph checked below shall apply (only
one of the paragraphs below should be checked, and if none or both of them are
checked, then the provisions of the first paragraph titled "Account Not
Restricted Immediately" shall apply):

             _X__   Account Not Restricted Immediately. Notwithstanding the
       provisions of Section 2(a) hereof, unless and until Creditor delivers to
       Depository an Order directing Depository not to act on Customer's
       Orders, Depository may continue to comply with Orders originated by
       Customer, including Orders for the withdrawal of funds from the Account,
       the payment of interest earned on the Account and the renewal or closing
       of the Account.

             ___    Account Restricted Immediately. Except as provided in this
       Agreement or as otherwise agreed to by Creditor in writing, as of and
       after the date of this Agreement Customer may not make debits to or
       withdrawals from the Account and shall have no access to the Account,
       and Creditor shall have exclusive access to the Account. If the Account
       is a certificate of deposit or other time deposit, then at the
       expiration of its term, unless Depository has received an Order to the
       contrary from Creditor, the Account shall be renewed for a term, which
       is equal to the immediately preceding term.

       (c)   Before Creditor attempts to give Depository any Orders concerning
the Account, Creditor shall deliver to Depository such documentation as
Depository may from time to time reasonably request to evidence the authority
of those partners, officers, employees or agents whom Creditor may designate to
give Orders.

       (d)   Unless otherwise agreed in writing between Depository and
Creditor, Depository will transfer funds from the Account to Creditor in
response to an Order from Creditor in accordance with this Agreement on a
Banking Day (a day on which Depository is open to conduct its regular banking
business, other than a Saturday, Sunday or public holiday), if Depository
receives the Order on such Banking Day before the deadline established by
Depository from time to time for such transfer requests, and the amount
requested to be transferred does not exceed the collected and available balance
in the Account at the beginning of such Banking Day as determined by Depository
after deducting the amount of all Returned Items (as defined in Section 3(a)
hereof).

       (e)   Unless otherwise agreed in writing between Depository and
Creditor, transfers of funds from the Account to Creditor shall be made using
the Fedwire system unless for any reason the Fedwire system is unavailable, in
which case Depository will determine the funds transfer system to be used in
making such transfer and the means by which such transfer will be made.
Creditor shall provide Depository with such information as Depository may
require to make such transfer, including the name and routing number of
Creditor's bank and the account number of Creditor's account at such bank to
which the funds are to be transferred. Customer and Creditor understand that a
funds transfer by Depository may be delayed or not made if the transfer would
cause Depository to violate any applicable law or regulation.

       3.    Priority of Creditor's Security Interest; Rights Reserved by
Depository.

       (a)   All of Depository's present and future rights against the Account
are subordinate to Creditor's security interest therein; provided however, that
Creditor agrees that nothing herein subordinates or waives, and that Depository
expressly reserves, all of Depository's present and future rights (whether
described as rights of setoff, banker's lien, chargeback or otherwise, and
whether available to Depository under law or any other agreement between
Depository and Customer concerning the Account, or otherwise) with respect to:
(i) any item deposited to the Account and returned unpaid, whether for
insufficient funds or for any other reason, and without regard to the
timeliness of such return or the occurrence or timeliness of any drawee's
notice of non-payment; (ii) any item subject to a claim against Depository of
breach of transfer or presentment warranty under the Uniform Commercial Code,
as adopted in the applicable state; (iii) any automated clearing house ("ACH")
entry credited to the Account and returned unpaid or subject to an adjustment
entry under applicable clearing house rules, whether for insufficient funds or
for any other reason, and without regard to the timeliness of such return or
adjustment; (iv) any credit to the Account from a merchant card transaction,
against which a contractual demand for chargeback has been made; (v) any credit
to the Account made in error; and (vi) Depository's usual and customary charges
for services rendered in connection with the Account. Items, entries, and
transactions described in clauses (i) through (v) of this paragraph are
hereinafter collectively referred to as "Returned Items".

       (b)   Except as otherwise required by law, Depository will not agree
with any third party to comply with Orders originated by such third party.

       4.    Returned Item Amounts. Customer and Creditor understand and agree
that Depository will collect the amount of each Returned Item by debiting the
Account. Customer shall pay the amount of each Returned Item immediately upon
demand to the extent there are not sufficient funds in the Account to cover
such amount on the day of the debit. Creditor shall pay to Depository, within
twenty (20) days after demand on Creditor by Depository, any such amount that
has not been paid in full by Customer within ten (10) days after demand on
Customer by Depository to the extent that Creditor received proceeds from the
corresponding Returned Item; provided however, that if Depository is stayed
from making such demand upon Customer as a result of a bankruptcy or similar
proceeding, then Depository shall be deemed to have made such demand upon
Customer at the commencement of such proceeding. Depository agrees that any
demand upon Creditor for payment of such amount shall be made within one
hundred twenty (120) days after termination of this Agreement.

       5.    Statements; Notices of Adverse Claims. Depository will send copies
of all statements for the Account simultaneously to Customer and Creditor.
Depository may disclose to Creditor such other information concerning the
Account as Creditor may from time to time request; provided however, that
Depository shall have no duty or obligation to comply with any such request.
Except as otherwise required by law, Depository will use reasonable efforts
promptly to notify Creditor and Customer if Depository receives a notice that
any other person claims that it has a property interest in the Account.
Customer and Creditor shall have thirty (30) days after receipt of a statement
of the Account to notify Depository of an error in such statement. Depository's
liability for any such error is limited in accordance with Section 6 hereof.

       6.    Depository's Responsibility.

       (a)   Except for permitting a withdrawal in violation of Section 2
hereof, Depository will not be liable to Creditor for complying with Orders
from Customer that are received by Depository before Depository receives and
has a reasonable opportunity to act on a contrary Order from Creditor.

       (b)   Depository will not be liable to Customer for complying with
Orders originated by Creditor, even if Customer notifies Depository that
Creditor is not legally entitled to issue Orders, unless Depository takes the
action after it is served with an injunction, restraining order, or other legal
process enjoining it from doing so, issued by a court of competent
jurisdiction, and has had a reasonable opportunity to act on the injunction,
restraining order or other legal process.

       (c)   This Agreement does not create any obligation of Depository except
for those expressly set forth herein. In particular, Depository need not
investigate whether Creditor is entitled under Creditor's agreements with
Customer to give Orders. Depository may rely on any and all notices and
communications it believes are given by the appropriate party.

       (d)   Depository will not have any liability to Customer or Creditor for
claims, losses, liabilities or damages resulting from any failure to comply
with Orders or delay in complying with Orders if such failure or delay is due
to circumstances beyond Depository's reasonable control.

       (e)   Depository will not have any liability to Customer or Creditor for
claims, losses, liabilities or damages suffered or incurred by Customer or
Creditor as a result of or in connection with this Agreement except to the
extent such losses, liabilities and damages directly result from Depository's
gross negligence or willful misconduct.

       (f)    In no event will Depository have any liability to Customer or
Creditor in connection herewith for any consequential, special, punitive or
indirect loss or damage whether or not any claim for such damages is based on
tort or contract or Depository knew or should have known the likelihood of such
damages in any circumstances.

       7.    Indemnity.

       (a)   Customer will indemnify Depository, its officers, directors,
employees, and agents against claims, demands, losses, liabilities, damages,
costs and expenses (including reasonable attorneys' fees and disbursements and
the reasonable estimate of the allocated costs and expenses of Depository's in-
house legal counsel and staff) arising out of this Agreement or Depository
following any Order or other instruction or request of Customer or Creditor in
connection with this Agreement, except to the extent the claims, liabilities,
costs and expenses are caused by Depository's gross negligence or willful
misconduct.

       (b)   Creditor will indemnify Depository, its officers, directors,
employees, and agents against claims, demands, losses, liabilities, damages,
costs and expenses (including reasonable attorneys' fees and disbursements and
the reasonable estimate of the allocated costs and expenses of Depository's in-
house legal counsel and staff), arising out of Depository following any Order
or other instruction or request of Creditor in connection with this Agreement,
except to the extent the claims, liabilities, costs and expenses are caused by
Depository's gross negligence or willful misconduct. Creditor will pay such
amount as may be due to Depository under this indemnity within twenty (20) days
of demand on Creditor by Depository to the extent such amount has not been paid
in full by Customer within ten (10) days after demand on Customer by
Depository; provided however, that if Depository is stayed from making such
demand upon Customer as a result of a bankruptcy or similar proceeding, then
Depository shall be deemed to have made such demand upon Customer at the
commencement of such proceeding.

       (c)   Creditor's and Customer's liabilities to Depository under this
Section are joint and several.

       8.    Termination; Survival.

       (a)   Creditor may terminate this Agreement by notice to Depository and
Customer. Depository may terminate this Agreement on thirty (30) day's notice
to Creditor and Customer; provided however that this Agreement may be
terminated immediately by notice from Depository to Creditor and Customer
should Creditor fail to make any payment when due to Depository hereunder.

       (b)    This Agreement shall terminate upon Depository's receipt of
written notice from Creditor expressly stating that Creditor no longer claims
any security interest in the Account.

       (c)   Sections 4, "Returned Item Amounts," 6, "Depository's
Responsibility," and 7, "Indemnity," will survive termination of this
Agreement.

       9.    Governing Law. This Agreement and the Account shall be governed by
and construed in accordance with the laws of the State of Texas. Depository may
not change the law governing the Account without Creditor's express written
consent, which consent shall not be unreasonably withheld.

       10.   Entire Agreement. This Agreement is the entire agreement and
supersedes any prior agreements and contemporaneous oral agreements of the
parties concerning its subject matter.

       11.   Amendments; Waivers. This Agreement may be amended or modified
only in writing signed by all parties hereto, and no waiver of any right under
this Agreement will be binding unless it is in writing and signed by the party
to be charged.

       12.   Severability. To the extent a provision of this Agreement is
unenforceable, this Agreement will be construed as if the unenforceable
provision were omitted.

       13.   Other Agreements. As long as this Agreement remains in effect,
transactions involving the Account shall be subject, except to the extent
inconsistent herewith, to the provisions of such deposit account agreements,
disclosures, and fee schedules as are in effect from time to time with respect
to the Account.

       14.   Successors and Assigns. The provisions of this Agreement shall be
binding upon and inure to the benefit of Depository, Creditor and Customer and
their respective heirs, executors, administrators, legal representatives,
successors and assigns.

       15.   Notices. All Orders, notices, requests and demands which any party
is required or may desire to give to any other party under any provision of
this Agreement must be in writing (unless otherwise specifically provided) and
delivered to each party at the address or facsimile number set forth below its
signature, or to such other address or facsimile number as any party may
designate by written notice to all other parties. Each such notice, request or
demand shall be effective on receipt. The delivery of any Order to Depository
shall be effective only if in writing, signed by Creditor, and delivered to
each of the addresses of Depository set forth below, addressed to the attention
of "Account Control Agreement Demands", by certified mail, return receipt
requested, or by traceable hand delivery. Electronic or facsimile delivery, or
any other non-conforming Order, shall not be binding upon Depository, although
Depository may in its sole discretion accept and act on Orders conveyed in any
manner, including orally, if believed to be authorized.



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       16.   Counterparts. This Agreement may be executed in counterparts, each
of which shall be an original, and all of which shall constitute but one and
the same instrument.

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

LOAN NUMBER:

DEPOSITORY:

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<CAPTION>

WELLS FARGO BANK, N.A.
<S>                                      <C>

By:                                     By:

Name: Rafael A. Valiente                Name: Don Kendrick

Title: Relationship Manager             Title: Regional President

Telephone: (512) 344-7430               Telephone: (512) 344-7202

Address of Account Officer:             Address of Regional President:

Wells Fargo Bank, N.A.                  Wells Fargo Bank, N.A.
Attn:  Account Control Agreement DemandsAttn:  Account Control Agreement Demands


111 Congress Avenue                     111 Congress Avenue
3rd Floor                               2nd Floor
Austin, Texas 78701                     Austin, Texas 78701
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<CAPTION>

VIKING ASSET MANAGEMENT, LLC   SOUTH TEXAS OIL CO.
<S>                             <C>

By:                            By:

Name:                          Name: J. Scott Zimmerman

Title:                         Title: Chief Executive Officer

Address:                       Address:
600 Montgomery Street          769 Highway 95 North
44th Floor                     Bastrop, Texas 78602
San Francisco, California 94111Attention: J. Scott Zimmerman, Chief Executive Officer
Attention:
                               Facsimile:
Facsimile:
                               Telephone:
Telephone:
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<S> <C> <C>

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<CAPTION>
ADDRESS FOR NOTICES:                  WITH A COPY TO:
<S>                                    <C> <C>
Wells Fargo Bank, National AssociationWells Fargo Bank, National Association
Attn:  Rafael A Valiente              Attn:  John B Smith
111 Congress Avenue, 3rd Floor        111 Congress Avenue, 3rd Floor
Austin, TX 78701                      Austin, TX 78701
Rafael.a.valiente@wellsfargo.com      John.b.smith@wellsfargo.com
Tel:  (512) 344-7430                  Tel:  (512) 344-8408
Fax:  (512) 344-7379                  Fax:  (512) 344-7379

                                      Wells Fargo Bank, National Association
                                      Attn:  Mark Curry
                                      111 Congress Avenue, 2nd Floor
*                                     Austin, TX 78701
*                                     Mark.J.Curry@wellsfargo.com
*                                     Tel:  (512) 344-7207
*                                     Fax:  (512) 344-7291

                                      Wells Fargo Bank, National Association
                                      Attn:  Don Kendrick
                                      111 Congress Avenue, 2nd Floor
                                      Austin, TX 78701
                                      Don.kendrick@wellsfargo.com
                                      Tel:  (512) 344-7202 / Fax:  (512) 344-7291
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