Geologic map of the Three Sisters Wilderness, Deschutes, Lane, and Linn counties, Oregon

The Wilderness Act (Public Law 88-577, September 3, 1964) and related acts require the U.S. Geological Survey and the U.S. Bureau of Mines to survey certain areas on Federal lands to determine the mineral values, if any, that may be present. Results must be made available to the public and to be submitted to the President and Congress. This report presents the results of a geologic survey of the Three Sisters Wilderness, Deschutes and Willamette National Forests, Deschutes, Lane and Linn Counties, Oregon