The area described in this report comprises 712 square miles centered on the City of Austin. The area extends north almost to Round Rock, south to the vicinity of Buda, east to just beyond Manor, and west to about 5 miles west of Oak Hill. It includes approximately 604 square miles of Travis County, 38 square miles of Hays County, 18 square miles of Bastrop County, and 52 square miles of Williamson County.

With the growing concern for finding new sources of energy, there has been renewed interest in an old source, lignite. In the past few years, Texas lignite has been "rediscovered", and a wave of lignite exploration rivals the early oil booms of Texas history. Present heavy leasing activity will be followed during the next decade by the development of numerous mines.

Geologic map that depicts the surface geology of Gaines and Andrews Counties and parts of Yoakum, Terry, Dawson, Martin, Winkler, Ector, and Midland Counties, Texas. The 5-page booklet indicates geologic formations, abbreviations, and ages.