The spatial data were obtained from the Texas Parks and Wildlife Department and are current as of 2007. Attributes were modified to include rock type, origin, color values, and identification numbers.

"1:250,000 Geology Data for Texas The Texas Geologic Atlas Project was first cited in the University of Texas - Bureau of Economic Geology (BEG) Report for 1961. In September of that year, compilation of the first of 38 Geologic Atlas of Texas (GAT) hardcopy map sheets began. The project, under the direction of Dr. Virgil E. Barnes, involved the work of 28 BEG geologists and many other geologists, seven cartographers, and several editors. The last GAT sheet was published in 1987, but the GAT has remained on the BEG "Best Seller" list of publications for many years and can be found at: http://www.beg.utexas.edu/mainweb/publications/pubs-bstsell.htm In October 2002, the United States Geological Survey (USGS), in cooperation with the Texas Water Development Board (TWDB), began development of an Environmental Systems Research Institute (ESRI) geodatabase model to capture the power of these data. Phase I (2002-2004) of this effort produced a library of 38 ESRI personal geodatabases representing the original 38 BEG map sheets. Phase II (2005-2006) involved the development of a Statewide Digital Geologic Atlas of Texas, combining the 38 personal geodatabases into one ESRI ArcSDE geodatabase containing more than 145,000 geologic features. Phase III (2007), continued to build on the work completed in the previous two phases with the inclusion of higher-resolution geologic data from the USGS STATEMAP program and on-going geodatabase refinement. The final product is an ESRI personal geodatabase consisting of four feature datasets, corresponding to the four different resolutions of geologic data. Each feature dataset includes two feature classes: rock units and faults. Where available, other geologic feature classes may be included inside the scale-appropriate feature datasets (i.e. member units, geologic contacts, volcanic vents, etc.). This dataset was created as part of the conversion of the 1:250,000 University of Texas, Bureau of Economic Geology Geologic Atlas of Texas map sheets." - TPWD