North Sister/South Ridge

Climb 5,000+ feet of elevation gain along a difficult ridge. The route crosses Collier Glacier before attaining the south ridge. This is the most difficult of Oregon's Three Sisters.

Getting There  

From Eugene, OR, drive OR-126 east and turn right onto OR-242 and continue to the  Obsidian Trailhead (4,800 ft).


Hike the Obsidian Trail 4.5 miles to Sunshine Shelter, at its junction with the Pacific Crest Trail.  A climbers trail continues southeast for 1.5 miles to Collier Glacier.  Continue across glacier on snow or scree to attain the south ridge.

Ascent Route  

Ascend the ridge directly or closely right of crest.  Traverse below the gendarme on the left and then regain ridge.  Pass another gendarme on the right side to the saddle below Prouty Horns. Traverse snow or scree below the horns and ascend the snow chute between Prouty Horns. Ascend the gully between the horns then scramble north to the summit.

Descent Route  

Descend the climbing route.

  • Suitable Activities: Climbing
  • Climbing Category: Basic Alpine
  • Seasons: May, June, July, August, September, October
  • Weather: View weather forecast.
  • Difficulty: Basic Glacier Climb
  • Length: 15.0 mi
  • Elevation Gain: 5,085 ft
  • 10,085 ft
  • Green Trails Three Sisters No. 621
  • USGS North Sister

Upcoming Activities

Basic Alpine Climb - North Sister/South Ridge

Climbing Trip
Climb one of the classic Sister volcanoes in central Oregon.
Difficulty: Basic Glacier Climb
Mon, Jul 2, 2018 - Wed, Jul 4, 2018
Prerequisites, Leader's Permission Required
1 participant
Registration closes Jul 11
Tacoma Branch
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