Gunsight Mountain (9263 ft) is located in the Lewis Range, Glacier National Park in the U.S. state of Montana. Gunsight Mountain is named after the adjacent Gunsight Pass, which was named by George Bird Grinnell in 1891.

Geology

Like other mountains in Glacier National Park, Gunsight Mountain is composed of sedimentary rock laid down during the Precambrian to Jurassic periods. Formed in shallow seas, this sedimentary rock was initially uplifted beginning 170 million years ago when the Lewis Overthrust fault pushed an enormous slab of precambrian rocks 3 mi thick, 50 mi wide and 160 mi long over younger rock of the cretaceous period.