Gunsight Mountain, Mountain summit in Glacier National Park, Montana, United States

Gunsight Mountain is a summit in the Lewis Range within Glacier National Park that rises to about 9,260 feet with two distinctive peaks. The northeast face is covered by Sperry Glacier, which is a defining feature of the mountain's appearance.

Gunsight Mountain takes its name from the adjacent Gunsight Pass, which George Bird Grinnell named in 1891. The mountain rises to 9,263 feet (2,823 m) in the Lewis Range of Glacier National Park, Montana. Its rock is sedimentary, laid down in shallow seas and later lifted along the Lewis Overthrust fault.

The mountain was named by George Bird Grinnell in 1891 because its two peaks resembled a gun sight when viewed from certain vantage points. This naming shows how early explorers connected unfamiliar landscapes to objects from their everyday experience.

The route begins at the Sperry Chalet Trailhead near Lake McDonald Lodge and passes through challenging terrain with significant elevation changes. Visitors should expect a strenuous climb and should have good physical fitness and mountaineering experience before attempting the ascent.

Gunsight Mountain is built of sedimentary rock laid down in shallow seas from the Precambrian to Jurassic periods. About 170 million years ago the Lewis Overthrust pushed a slab of Precambrian rock roughly 3 miles thick, 50 miles wide and 160 miles long over younger Cretaceous rock.