Consists of the Aztec Sandstone. Unit is a friable fine- to medium-grained sandstone with conspicuous large scale cross-strata (Stewart and Carlson, 1978). It is considered eolian. Its age is wholly Jurassic and does not include Triassic rocks as indicated on the 1978 State map (Stewart, 1980). The Aztec is the westward continuation of the Navajo Sandstone of the Colorado Plateau. It crops out only in southern Nevada in Clark and Lincoln Counties.