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Thompson Peak

Sun Valley

Standard route to the tallest summit in the Sawtooths.

Alpine Climbing Easy

20 km
1.2 km
1.2 km
Low Point
2 km
High Point
3.2 km
Thompson Peak Map

Thompson Peak is the highpoint of the Sawtooth range at 10,751 feet, making a coveted summit for Idaho peakbaggers. Traffic on the mountain remains light, however, thanks to the long approach which is largely off-trail. The scramble to the summit is easier than many other Sawtooth peaks, but still enough to present a challenge for most. Described here is the route up the southwest couloir, which makes the standard ascent. It requires nothing tougher than Class 3 in typical condition, but a sizable talus-hopping approach as well. Early season can present more difficulty with snow and ice.


Starting along Alpine Way trail from Redfish Lake, any glimpse of the mountain reveals an imposing, nearly vertical fortress of rock on its east face. The hidden west side is more forgiving, however, and that’s eventually where the hike leads. You’ll depart Alpine Way on an unmarked climbers’ trail which rises along rocky slopes and through a small meadow, to then traverse above an unnamed lake. Thompson Peak rises directly beyond, and the trail disappears into talus. Continue working along the slope above the lake, aiming for the saddle up ahead. You’ll pass a small tarn then scramble up a steep boulder field to reach the saddle.

From there you’ll cross onto the west slope of Thompson, and choose your route to access the base of the couloir. You can make a rising traverse across the face, or sidehill all the way across then go straight up. Either way, it’s a long traipse over broken, textured granite and possibly snow, and you’ll have to find a gap in one low cliffband along the way Heading up the couloir should not be much more difficult, but you can expect a few steeper sections. If the moves start feeling like Class 4 or 5, then you are likely in the wrong chute. Beware of loose rock anywhere.

A brief hand-and-foot scramble tops the final section. On top are twin blocks with a flat space in between, altogether enough for a handful of people to comfortably share the summit. But the chances are, you won’t see anyone besides your own party here on the roof of the Sawtooths. Views stretch up and down a spire-studded horizon, revealing most of the prominent Sawtooth Peaks plus the White Cloud mountains beyond the valley.

Sources: https://www.summitpost.org/thompson-peak/153013 https://stanleycc.org/blogs/articleid/479/into-the-belly-of-the-mountain-climbing-thompson-peak



The ascent involves simple glacier hiking and/or short, straightforward rock scrambles. Equivalent to Alpine F, F+

High Exposure

3 out of 4

Much of the route is difficult to protect and a fall could be disastrous at certain points.


3 out of 4

Little chance of being seen or helped in case of an accident.

Best time to visit

between June and October

Similar routes nearby

Guidebooks in this area