The Flathead Tunnel: A Geologic, Operations, and Ground Support Study, Burlington Northern Railroad, Salish Mountains, Montana by Eugene H. Skinner 

Bureau of Mines Information Circular IC-8662

United States Department of the Interior

1974 Staple Bound Paperback, 98 pages

Complete with assigned geologic map in back pocket.

Details related to construction of the 7-mile long Burlington Northern Railroad Flathead Tunnel project in Montana, 1966-1969.