Elevation: 8,740 ft
Prominence: 45

This peak is not in the book. Published October 2025
Peak 8740 South is an overlooked summit that sits at the headwaters of Poison Creek, Warm Spring Creek, and Trail Creek in the Lemhi Range. It is best climbed in combination with nearby Watson Peak (8,671 feet). USGS Poison Peak

Peak 8740 South (in mid-ground) as viewed from Watson Peak to its northeast. Livingston Douglas Photo
Access
Same as for Watson Peak. This is the second leg of a 3-peak adventure that includes Watson Peak, Peak 8740 South, and Poison Peak (9,364 feet). It covers 8.5 miles with 3,115 feet of elevation gain round trip.
Map Errors
The USGS topo map shows a trail heading down Warm Spring Creek from the saddle north of Peak 8740 South. That trail no longer exists. The trail coming up from Saddle 8205 to the 8,340-foot connecting saddle north of Peak 8740 South reaches the saddle on its southwest end. The USGS topo map incorrectly shows this trail crossing the north ridge of Peak 8740 south. The trail section near Saddle 8205 no longer exists.
North Ridge, Class 2
The Climb
From the 8,340-foot connecting saddle with Watson Peak, head south to get through a minor finger of thick pine forest to reach/stay in open scrub. Head right/west-southwest to reach the ridge crest. Follow the ridge south then southwest, avoiding forested patches on or near the ridge, to reach the [lower] north summit. The ridge terrain is easy, short grass and scrub. From the north summit, continue a short distance south to the true/south summit. The summit hump is bare and has a fence row on it. I built a modest cairn on top.

The elusive, gentle summit of Peak 8740 South as viewed from high on the north ridge. This was my ascent route. Livingston Douglas Photo

The summit of Peak 8740 South with Poison Peak in the distance (just left of center). Livingston Douglas Photo
Northwest Shoulder, Class 2
The Descent
From the south summit, return to the north summit. Descend a steep, rocky, loose unmapped 2-track road to reach Saddle 8205. Saddle 8205 is the connecting saddle with Poison Peak. Itconcludes the second leg of today’s 3-peak journey. Poison Peak (9,364 feet) is up next.
Additional Resources