Exhibit 99.1 - Resignation Letter (Conrad Humbke)

Murray Conradie
Chairman/Chief Executive Officer
South Texas Oil Company
2802 Flintrock Trace, Suite 252
Austin, TX 78738

August 27, 2007

Re:    Resignation from South Texas Oil Company

Dear Murray,

        I  have  enjoyed  my  tenure  as a Director of South Texas Oil Company.
Together, we have helped grow the company into an outstanding organization with
truly tremendous opportunities ahead.    However,  I  am  unable to continue to
give South Texas Oil Company the full-time attention it deserves.  Please allow
this letter to serve as written notification of my resignation as a Director of
South Texas Oil Company, to be effective August 27, 2007.

       I have not had any disagreements with management or  the  company on any
matter  relating  to  the company's operations, policies or practices.  To  the
contrary, I have tremendous appreciation for you and the rest of the Board.

       I look forward to  the  endeavors  and  successes that are sure to be in
your future.

                          Best regards,
                          /s/ Conrad Humbke
                          -----------------
                          Conrad Humbke