The trek to this classically craggy, 10,751-foot summit makes for a long day or sweet overnight. Either way, it belongs on any peak lover’s must-do list because it provides one of those wild journeys that only a remote mountain can deliver. Thompson lords over its surroundings, with a jaw-dropper view of the Stanley Valley and the Sawtooths’ jagged spine.
To reach it, hike 6.5 miles (one-way) and gain 4,200 feet from the Redfish Lake backpacker’s parking lot. Follow the Fishhook Creek Trail northwest on timbered ridgelines to an unnamed lake basin at 9,000 feet; find good campsites here if you’re overnighting. The rest of the route is off-trail: Climb to the 9,800-foot saddle between Thompson and Williams Peaks. From there, swing south around the far (west) side of Thompson. Traverse across talus on Thompson’s west face to a ridgeline saddle southwest of the summit, and make the final ascent by following climber trails through the cliff bands above. (This route is not technical until the last 50 feet—an exposed scramble to gain the summit block. Pack an ice axe for added security on snowfield crossings.)
The Way Five miles south of Stanley, on ID 75, take Redfish Lake Road west; go two miles to the trailhead. Map USFS Sawtooth National Forest Ketchum (North) ($14, see Contact)
Contact (208) 774-3000; fs.fed.us/r4/sawtooth