Also, if you don't already have it:

Texas Historical Commission
http://www.thc.state.tx.us/
P.O. Box 12276
Austin, TX 78711-2276
Phone: 512/463-6100
Home of the Texas cemetery preservation program. The website contains information on the preservation of threatened cemeteries and a printable booklet on cemetery preservation guidelines. Click on “cemeteries” and “preserving cemeteries.”