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 SR-126 east and turn right onto SR-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.


Standard glacier gear.


  • Guidebook: Best Climbs: Cascade Volcanoes by Jeff Smoot (FalconGuides 2012).
  • 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
  • USGS Trout Creek Butte, OR
  • Green Trails Bend - Three Sisters No. 622SX
  • USGS North Sister, OR
  • Green Trails Three Sisters No. 621
  • Green Trails Broken Top No. 622
Trip Reports

There are no resources for this route/place. Log in and send us updates, images, or resources.