Ruth Glacier, Glacier in Denali National Park, Alaska.

Ruth Glacier is a 50 km glacier in Denali National Park and Preserve, Alaska, beginning near the summit of Denali. Its Great Gorge is about 2 km wide and drops roughly 600 m over 16 km, with crevasses across the surface. Granite cliffs up to 1,500 m rise on both sides, and a dark moraine band separates the ice from the mountain base.

The glacier was named in 1903 by explorer Frederick Cook, who discovered it during his expedition through the Denali region. Cook chose the name of his youngest daughter, connecting this geographic location to his family.

The granite walls around the Ruth Gorge carry names given by climbers and mapmakers: the Mooses Tooth, Mount Dickey, Mount Bradley, Mount Wake, Mount Johnson and London Tower. Their faces hold highly technical ice and rock routes. The glacier itself was named in 1903 by Frederick Cook after his youngest daughter, Ruth.

Visitors can only reach this location through authorized air services that operate from designated landing areas within the park. It is important to book in advance, as weather conditions in this mountainous area often affect flights.

A 2024 open-licence research project estimated the Great Gorge to be 8,085 feet (2,464 m) deep, the deepest in North America. The drop from Mount Dickey's rim to the valley floor beneath the ice exceeds 2,400 m. The glacier was measured at 4,000 feet (1,200 m) thick in 1983.