1. Summary geochemical maps for samples of rock, stream sediment, and nonmagnetic heavy-mineral concentrate, Sweetwater Roadless Area, Mono County, California and Lyon and Douglas Counties, Nevada Yale Public content 1986. 2002-06-01T04:00:00Z. 2002-06-01T04:00:00Z. Geological Survey (U.S.). The Survey ; For sale by Branch of Distribution, U.S. Geological Survey. English. Public. California, Mono County, and Nevada.