Avalanche Lake, Mountain lake in Glacier National Park, Montana.

Avalanche Lake is a mountain lake in Glacier National Park, southwest of Bearhat Mountain, fed by meltwater from Sperry Glacier. Waterfalls drop from the cliffs above into the lake, and Avalanche Creek drains it, flowing on toward Haystack Creek. A survey in August 1910 measured its maximum depth at 63 feet near the upper end.

Dr. Lyman Sperry named the area Avalanche Basin in 1895 after observing multiple snow slides during a scientific expedition. The name later became established for the entire region and the valley leading to the lake.

The lake's name comes from the avalanches Dr. Lyman Sperry's 1895 party watched from the basin. Anglers come for westslope cutthroat trout, native here though most similar Glacier lakes hold no fish. The 2-mile approach follows Avalanche Creek from the Trail of the Cedars.

The trail to the lake is moderately easy and passes through forest with some elevation gain along the way. A wooden boardwalk at the beginning accommodates visitors with mobility concerns, though the path becomes more natural and steeper after that section.

Avalanche Lake is one of the few lakes of its size and elevation in Glacier National Park that holds fish; westslope cutthroat trout are native here, which makes it a popular spot for anglers. The lake was measured at 63 feet (19 m) deep near its upper end in August 1910.