Old Desolate is a 7,137-foot (2,175 m) multi-summit, ridge-like mountain located in Mount Rainier National Park, in Pierce County of Washington state.

[5] It is part of the Cascade Range, and lies five miles (8.0 km) due north of the summit of Mount Rainier.

[5] Old Desolate is located in the marine west coast climate zone of western North America.

[4] Most weather fronts originating in the Pacific Ocean travel northeast toward the Cascade Mountains.

As a result, the west side of the Cascades experiences high precipitation, especially during the winter months in the form of snowfall.