West Flank and Southwest Ridge over Irving Peak

Is it right for you?

Mount SoSo (once UN 13,417) sits about a mile south-southeast of Mount Oso in the remote Rock Lake and Moon Lake group of the Weminuche Wilderness. It's usually climbed with Irving Peak from a camp at Moon Lake.

From the Hunchback Pass trailhead, the Vallecito Trail crosses the pass and descends 5.75 miles to Rock Creek. The Rock Creek trail climbs about 4.15 miles to Rock Lake, and a rougher trail crosses a 12,420-foot pass to Moon Lake, about 11.9 miles from the trailhead. Many people take two days to get there. From camp, you cross the saddle between Oso and SoSo, drop west, climb Irving Peak's north ridge, then come back east and climb SoSo's west slopes to its southwest ridge. SoSo itself is Class 2; the steep couloir onto Irving's ridge is the hardest move of the day.

The round trip is about 30.3 miles with 10,075 feet of gain. From Moon Lake, the loop over both peaks is roughly 6.5 miles and 3,775 feet. Strong parties can add Mount Oso. Mileage and gain are our estimates.

Plan of the day

This week on the summit

Getting there

This trailhead needs a high-clearance 4WD, and you should allow as much as two and a half hours from Silverton. From the northeast end of Silverton, take County Road 2 up the Animas about 4.2 miles to Howardsville. Turn right up Cunningham Gulch, then take the left fork onto the Stony Pass road. It climbs steeply over the pass and down the far side. You will ford Pole Creek, then turn right at a fork and ford the Rio Grande. Both fords are harder early in the summer. Then follow the Beartown road about 4 slow, rough miles past the old Beartown site and up a rocky, rutted stretch. The Hunchback Pass trailhead is about half a mile below Kite Lake, at roughly 11,800 feet, with limited parking.

You can also reach this area from Creede or Lake City by driving to Rio Grande Reservoir, but the road west of the reservoir has very rough sections. There is some camping near the trailhead and near the old Beartown site.

Conditions on Stony Pass and the Beartown road change from year to year, so check before you go. Trips from here into the Weminuche usually take several days.

Next: the route, step by step →

The route

1. 1

   Moon Lake camp 11,670' · 0 mi

   Camp is about 11.9 miles from the trailhead (see the overview). Walk back to the north shore, leave the trail and climb steeply west up a valley of willows and tall plants.

2. 2

   Basin east of Mount Oso 12,100' · 0.5 mi

   After about 400 feet the slope eases. Cross the basin toward the Oso–SoSo saddle; of its two low points, the southern one is easier. Light quartzite meets dark rock right at the saddle.

3. 3

   Oso–SoSo saddle 12,800' · 1 mi

   Climb rubble to the saddle, then drop about 600 feet west on small broken rock and scree.

4. 4

   Col on Irving's north ridge 12,900' · 2.2 mi

   Contour across the broad valley (elk trails help) and climb a steep, flowery tundra valley toward the col between Irving's north ridge and Point 13,006. It narrows to a couloir of rock and mud, and the last 20 feet have almost no solid footing.

   Watch for: Very poor footing at the top; a short rope or sling can help.

5. 5

   Irving Peak 13,216' · 2.75 mi

   Walk south on the ridge, level at first, then steeper, stepping around a few big rocks. It's Class 2.

6. 6

   Pond below SoSo 12,200' · 3.75 mi

   Go back to the col and down the couloir. Contour east on game trails to a tiny pond just under 12,200 feet and cross the stream.

7. 7

   Southwest ridge 13,200' · 4.5 mi

   Climb southeast up SoSo's west slopes through shallow gullies, tundra benches and a few boulder patches to a flat spot on the ridge at about 13,200 feet.

8. 8

   Mount SoSo 13,421' · 4.75 mi

   Turn left and walk a quarter mile over small brown rock to the top.

Getting down

Head down the east ridge (Class 2 to 2+). Big rocks block the crest, so work carefully along its south side for about 500 feet, then cross north at a flat spot and descend into the basin west of Moon Lake through talus, tundra benches and small cliffs. Finish east through willows and marshy ground to the lake.

The north ridge to the Oso saddle is reported to have a short Class 4 bit; avoid it.

If things go wrong

From the pond below SoSo, head northeast back over the Oso–SoSo saddle to Moon Lake.

Last step: check in before you go →

3D flyover

See the trail on video

Other routes

Every way up Mount SoSo we list, with its class.

• Mount Soso West flank & SW Ridge this routeClass 2 34.05 mi
• Irving Lake Approach (Alternate)Class 2+ 21 mi

Check in before you go

Send someone your peak, route, trailhead and when you’ll be back. If you’re late, they know where to send help.