SECOND AMENDMENT TO
EXECUTIVE EMPLOYMENT AGREEMENT
THIS SECOND AMENDMENT TO EXECUTIVE EMPLOYMENT AGREEMENT (the "Second
Amendment"), dated effective as of the 21st day of August, 2000, is by and between South Texas Drilling &
Exploration, Inc., a Texas corporation, with its principal place of business at 9310 Broadway, Building 1, San
Antonio, Bexar County, Texas (the "Company"), and William Stacy Locke (the "Employee").
WHEREAS, the Company and the Employee entered into that one certain Executive Employment Agreement
dated effective as of the 25th day of April, 1995, and as amended by that one certain First Amendment to
Executive Employment Agreement dated effective as of the 16th day of November, 1998 (said Executive
Employment Agreement, as amended, herein referred to as the "Employment Agreement").
WHEREAS, the Company and the Employee hereby desire to modify and amend certain terms and provisions of
the Employment Agreement and to approve, ratify and confirm the Employment Agreement, as modified and
amended by this Second Amendment.
NOW, THEREFORE, in consideration of the premises and mutual agreements herein set forth, the parties hereto
have agreed, and do hereby agree, as follows:
A. Section 1 of the Employment Agreement is hereby modified and amended as necessary to provide that:
1. The Company employs, as of the date of this Second Amendment, and will employ Employee in the business
of the Company as its President and Chief Financial Officer, and the Employee works, as of the date of this
Second Amendment, and will continue to work for the Company as its President and Chief Financial Officer, for
the period beginning as of August 15, 2000 and ending April 30, 2003, and thereafter from year to year
(renewing automatically upon expiration of the employment term ending April 30, 2003 and upon expiration of
each one year employment term thereafter), unless and until such employment shall have been earlier terminated
as provided in the Employment Agreement, as amen