At the request of the U.S.Bureau of Land Management, the Gold Creek (OR-003-033) and Sperry Creek (OR-003-035) Wilderness Study Areas, comprising approximately 15,780 and 5,600 acres, respectively, were evaluated for mineral resources and mineral resource potential. Throughout this report, "wilderness study area" and "study area" refer to the combined 21,380 acres for which mineral surveys were requested. The U.S. Geological Survey and the U.S. Bureau of Mines conducted geologic, geochemical, and geophysical surveys to assess the identified mineral resources (known) and mineral resource potential (unknown) of the study area. Field work for this report was carried out in 1987, 1988, and 1989.