Elevation: 11,090 ft
Prominence: 310

This peak is not in the book. Judi Steciak and Carl Hamke provided the following route information. See their article on the Missing Eleveners in the Climbing History Section of this site. Pat McGrane provided five photos showing the peak and the route.
Peak 11090 splits the East Fork Pahsimeroi River into its west and east branches 2.5 miles east of Leatherman Peak. A cliff band shrouds the base of the mountain’s West Side. USGS Leatherman Peak

Peak 11090 is the mountain in the sunlight with the flat profile, as viewed from Cleft Peak. The East Fork Pahsimeroi Road is hidden in the canyon in the lower right side. Pat McGrane Photo
Access
From the end of the East Fork Pahsimeroi Road [(C)(3.2) on Page 294].
Northwest Ridge, Class 2
From your parking spot, wade the East Fork Pahsimeroi River and hike up the Breitenbach Pass Trail for about a half mile. Leave the trail and head up the West Fork until you are below the West Face of the peak. Walk up and follow the base of the cliffs northward until you find weaknesses near their twist to the east. Work up through breaks in the cliffs to easier slopes that lead to the Northwest Ridge. Follow the ridge to the summit. Continue past the summit for a view of a natural arch in the convoluted ridge that connects with No Regret Peak.
Pat McGrane Photos

The rest of the climb is on relatively stable talus. Alex Feldman on the upper slopes of Peak 11090 with Mount Borah in the background.

Peak 11090 as viewed from the summit of Mount Borah. Peak 11090 was unnamed in 1954 and remains unnamed today. Evilio Echevarria Photo
Additional Resources
Regions: EASTERN IDAHO->Lost River Range
Mountain Range: Lost River Range
Longitude: -114.61 Latitude: 44.087