Elevation: 7,631 ft
Prominence: 381
This peak is not in the book. Published November 2018
Peak 7631 is the highest of three scrub-covered hills above the large meadow at the confluence of the mouths of the three Sulphur Canyons (North, Middle, and South). Peak 7470 and Peak 7389 are the other two hills. All three of these ranked summits are visible from the junction of North Sulphur Canyon Road and South Sulphur Canyon Road. I unofficially call them The Three Sisters. The easiest ascent route for Peak 7631 is via its east ridge/north spur as accessed from a jeep road in the upper section of Middle Sulphur Canyon. I doubt that this peak sees many visitors. USGS Johnson Creek
Middle Sulphur Canyon/West Ridge, Class 2
Access
Same as for the south face of Peak 7389. This route is part of a ridge traverse from Peak 7389 to Peak 7631.
The Climb
From the 6,300-foot level near the mouth of Middle Sulphur Canyon, climb southeast up the north side of the West Ridge of Peak 7631 in open terrain between sections of forest. Stay just below the forest line higher up and angle diagonally onto the West Ridge. Once on the ridge, you will notice that the right/south side of the ridge is open desert scrub, in contrast to the thickly forested left/north side. Climb eastward up the ridge crest (or just right/south of it) in open terrain, finding a game/sheep trail to expedite your ascent.
You will soon reach a flattish section of the west ridge that appears to be the Northwest Spur of the ridge on the USGS topo map. The elevation here is about 6,900 feet. There is a bit of ridge chop in this northwest strip of the west ridge. The terrain in this section is a mix of field grass and scattered trees. After some minor ups and downs, cross a patch of aspen trees in a minor saddle using a helpful game trail.
After you emerge from the aspens, you reach the open terrain of the west ridge. It is now smooth sailing all the way to the summit. A game trail near the ridge crest will help you early on, but it disappears higher up. You will make quick work of this open, easy scrub. The summit of Peak 7631/South Sister is a gentle hump with a small rock cairn.
West Ridge/South Sulphur Canyon, Class 2+
Access
Same as for the Middle Sulphur Canyon/West Ridge Route. This is part of a ridge traverse and loop route from Peak 7389 to Peak 7631 with a return to the parking area at the junction of North Sulphur Canyon Road and South Sulphur Canyon Road.
The Descent
From the summit, descend the west ridge down to the flattish northwest spur and follow it to its west edge. Below this spur, there is no “west ridge” to speak of; it’s really more of a face. Descend west then southwest down the face. Stay to the left/north to avoid the thick forest. You have three options in descending this face: a gully in the center of the face, a shoulder on the right/north side of the face, and a shoulder on the left/south side of the face. It is best, and easiest, to descend the shoulder on the left/south side of the face.
Whichever route you choose to descend, you must angle left/southwest as you approach South Sulphur Canyon Road. A straight westerly drop to the open field/meadow is not a good idea due to very thick brush/veg at the base of the west face. The descent from the northwest spur down to South Sulphur Canyon Road is quite steep with a loose gravel/scree base. Take the descent slowly to avoid losing your footing. There is a final, short section of tall, thick veg to bash through to reach the [blessed] road. Once on the road, walk westward for about a mile to get back to the parking area at the junction of the South Sulphur Canyon Road and North Sulphur Canyon Road.
Additional Resources
Regions: Aspen Range->Peale Mountains->SOUTHERN IDAHO
Mountain Range: Peale Mountains
First Ascent Information:
- Other First Ascent: Middle Sulphur Canyon/West Ridge
- Year: 2018
- Season: Summer
- Party: Livingston Douglas
- Other First Ascent: West Ridge/South Sulphur Canyon -Descent
- Year: 2018
- Season: Summer
- Party: Livingston Douglas
Longitude: -111.47501 Latitude: 42.64459