Red Castle is a prominent mountain summit in northeastern Utah within the High Uintas Wilderness of the Uinta-Wasatch-Cache National Forest. Rising 12,676 feet on a spur along the crest of the Uinta Mountains in the Rocky Mountains, it is the state's 36th-highest summit. It is widely regarded as one of the High Uintas' signature peaks because of its distinct form and unusual visual prominence. The mountain rises about 1,500 feet above East Red Castle Lake in only half a mile, creating dramatic relief. Its runoff flows north through Smiths Fork and Blacks Fork to the Green River, and its upper slopes and summit have tundra conditions within a subarctic climate.