Bridger Wilderness and Green-Sweetwater Roadless Area, Wyoming

A mineral-resource appraisal of the Bridger Wilderness and contiguous Green-Sweetwater Roadless Area was made by the USGS and USBM in 1980-1982. This rugged and remote region along the west slope of the Wind River Range, Wyoming is mostly Precambrian crystalline granitic rocks that contain only small and discontinuous areas of mineralization. The area is considered to have little promise for metallic mineral deposits. Sedimentary rocks in the area have minor coal seams and beds of phosphate rock, but the coal beds are thin and of limited extent, and the phosphate rock is low-grade compared to similar rocks elsewhere in the region. A probable potential for oil and gas at depth, assigned to part of the area, is based on the assumption that oil- and gas-bearing rocks exist at depth below a low-angle thrust fault and a wedge of Precambrian crystalline rock.