This paper presents the areal geology of the Tecopa area, which may be the root zone of the Amargosa thrust and other sheets described in the Death Valley (Virgin Spring) region, California (Noble, 1941). The stratigraphy of the Algonkian and Cambrian strata in the Tecopa area was studied by Hazzard assisted by the writer. The present map (Pl. 2) is an attempt to utilize the published stratigraphic units of Hazzard and Hewett as cartographic units, in parts of the Shoshone and Tecopa quadrangles, southeasternmost Inyo County, California. More than 16,000 feet of Cambrian and Algonkian strata is involved in structural complexity suggesting westward thrust faulting on a large scale. The sedimentary section apparently has been skidded off the rigid Archean basement, and similar skidding of younger over older beds occurs higher in the section at two or three horizons. Movement in nearly all cases seems to be to the west, a fact not yet harmonized with directions of movement reported in neighboring areas. High-angle faults, including those of the Basin Range faulting, are mapped.