(Montana) Oscar Dingman. Placer-Mining Possibilities in Montana

34 pp. Illus. with folding maps, drawings, and blueprints. 10.75x8.25", mottled gray wrappers. Second Edition. Butte: Montana School of Mines, 1933.

Blueprints for how to build numerous types of riffles, a gold rocker, and more. Folding maps are impressive. Near fine.