Search U.S. government technical reports digitized or harvested by TRAIL.
Aerial tramways in the metal-mining industry.
Reconnaissance of placer mining in Boise County, Idaho
Gold mining and milling in the Wickenburg area, Maricopa and Yavapai Counties, Ariz.
Reconnaissance of placer mining districts in Idaho County, Idaho
Reconnaissance of placer-mining districts in Lemhi County, Idaho
Aerial tramways in the metal-mining industry :construction and operating costs