Uranium minerals have been found at several localities in west Texas. In the King Mountain area in southwestern Upton County carnotite forms coatings along joint planes and in borings in marineCretaceous limestone.

Fall Prong quadrangle is in the marginal portion of the Edwards Plateau near the southeastern corner of the Llano region. Almost three-quarters of the quadrangle is within the Edwards Plateau, and the rest consists of valleys of the Llano basin cutting back into the plateau.

Rocks exposed in the Cathedral Mountain quadrangle in the southeastern DavisMountains of Trans-Pecos Texas are assigned to the Word formation and to Capitan limestone in the Permian Guadalupe series; to the Maxon sandstone, Edwards limestone, Georgetown limestone, and Grayson (Del Rio) marl in th