Mineral resource potential of the Centennial Mountains Wilderness Study Area and contiguous areas, Idaho and Montana

The mineral resource potential of the proposed wilderness area was evaluated by teams of geologists, geochemists, and geophysicists from the U.S. Geological Survey and the U.S. Bureau of Mines.  The Geological Survey team's appraisal is based on geological, geochemical, and geophysical surveys of the area.  The U.S. Bureau of Mines economic appraisal is based on an examination of all mines, prospects, and quarries in the area, sampling of the various units within the Phosphoria Formation noted for their contained phosphate, and estimates of tonnages and grades of the contained phosphate.