Exhibit 99.1 - Resignation Letter Rickey Cooksey December 31, 2007 Murray Conradie Chairman/Chief Executive Officer South Texas Oil Company 769 Hwy. 95 N. Bastrop, Texas 78602 Re: Resignation from South Texas Oil Company Dear Murray, Please accept this as formal notice of my resignation from the position of Chief Financial Officer of South Texas Oil Company effective December 31, 2007. It has been a pleasure working with the management and staff of South Texas Oil Company and I thank you for such opportunity. Respectfully, /s/ Rickey Cooksey Rickey J. Cooksey