A summary of uranium-vanadium mining in the Carrizo Mountains, Arizona and New Mexico, 1920-1968
— William L. Chenoweth

Outcrops containing uranium-vanadium minerals in the Carrizo Mountains, Apache County, Arizona and San Juan County, New Mexico, were discovered about 1918 by John F. Wade of Sweetwater Trading Post. Although similar occurrences in Colorado were being mined for their radium content, the ones in the Carrizo Mountains could not be, since the Navajo Indian Reservation was closed to prospecting and mining. The ore deposits occur in fluvial sandstone beds of the Salt Wash Member of the Upper Jurassic Morrison Formation. The orebodies were formed by the selective impregnation of the sandstone and absorption by mudstone and fossil plant material, and are commonly associated with derital carbonaceous plant material in the sandstone. The orebodies are roughly tubular in cross-section and irregular in plan. They range from a feather edge to 10 ft in thickness, with an average thickness of 3 ft. The deposits were called carnotite type after the bright yellow mineral carnotite, a potassium uranium vanadate. Later work has identified tyuyamunite, a calcium uranium vanadate, and meta-tyuyamunite as the only uranium minerals in the Carrizo deposits. Vanadium clay and montrosite are also present. All of the known deposits are well oxidized.