Love Ranch and Miles Ranch quadrangles are in the Wind River Basin, Wyoming (fig. 1). The rocks exposed in the quadrangles are sedimentary, and range in age from Late Cretaceous to early Tertiary. The youngest formation in the quadrangles, the Wind River formation of Eocene age, is uranium bearing in adjacent areas. Within the two quadrangles the Wind River formation unconformably overlies all the older rocks. In Miles Ranch quadrangle the Wind River formation is divided, on the basis of photointerpretation, into an upper and lower unit; the relationship of these units to units of the Wind River formation, as mapped in adjoining areas, has not been determined.