Castle Peak, at 11,815 feet (3,601 m) high is the highest peak in the White Cloud Mountains of Idaho. Castle Peak is the 25th highest peak in Idaho, and the 9th most prominent peak in the state. Castle Peak is located within the Sawtooth National Recreation Area in Custer County. The towns of Stanley, Idaho and Challis, Idaho are both about 21 miles (34 km) from Castle Peak, Ketchum, Idaho is about 27 miles (43 km) from the peak. Castle Peak is located in the largest roadless area in the lower 48 states that is not a designated Wilderness Area.