The Hueco Bolson is a segment of the Rio Grande Rift that formed as a result of late Tertiary Basin and Range deformation. The upper Tertiary Fort Hancock Formation and the upper Tertiary-Quaternary Camp Rice Formation compose the basin fill except in the deepest (western) parts of the bolson. Five lithofacies form the Fort Hancock Formation: (I) gravel; (II) sand, sandy mud or sandy silt, and gravel; (III) sand, sandy mud, and sandy silt; (IV) clay and sandy clay; and (V) clay, mud, sandy mud, and gypsum.

The Lower Cretaceous Travis Peak Formation contains an estimated 6.4 trillion cubic feet (Tcf) of gas in place in East Texas and North Louisiana. Advanced technology will be needed to maximize recovery from this low-permeability ("tight") gas sandstone. This report focuses on the contribution of geology to understanding and efficiently developing the complex gas reservoirs in the Travis Peak Formation in East Texas.

The Hueco Basin of Trans-Pecos Texas, which formed in response to Cenozoic extensional tectonism, lies within the southern Rio Grande rift near the poorly defined boundary between the rift and the southern Basin and Range province. Subsurface data, including proprietary seismic lines, were studied in conjunction with aerial-photo and surface geologic mapping to determine the basin's structure and fault history. These data were also studied to evaluate the seismic risk of the basin and to consider it as a possible repository of low-level radioactive waste.