Thompson Peak is the highest peak in the Sawtooth Range of Idaho. Its 10,751 ft summit is located within Custer County, although some of the lower portion of the mountain is in Boise County. Thompson Peak is also located within the Sawtooth Wilderness portion of the Sawtooth National Recreation Area, a unit of Sawtooth National Forest. The town of Sta…Thompson Peak is the highest peak in the Sawtooth Range of Idaho. Its 10,751 ft summit is located within Custer County, although some of the lower portion of the mountain is in Boise County. Thompson Peak is also located within the Sawtooth Wilderness portion of the Sawtooth National Recreation Area, a unit of Sawtooth National Forest. The town of Stanley, Idaho is about 6 miles northeast of Thompson Peak.