Pets allowed
Not Allowed
Elevation Gain
5,757.00 ft (1,754.73 m)
Trail type
18.90 mi (30.42 km)
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At 10,318 feet above sea level, South Sister provides stunning views of the Cascade Range and a feeling of self accomplishment that can only be attained from summiting a mountain of this magnitude. When it comes to mountains that are over 10,000 feet, South Sister is unique in that technical mountaineering experience and equipment isn’t necessary, because it is accessible via the 11-mile there-and-back South Sister Climber Trail #36. However, with accessibility comes popularity, and this path is often clogged with hikers eager to experience this awesome display of nature. Although some don’t mind a crowd, if you’re someone that prefers solitude as you hike, there is an alternative route that takes you up the east side of South Sister before eventually meeting up with South Sister Climber Trail for the last portion of the journey.

If you choose to take this route, your first destination will be the three bodies of water that make up Green Lakes. Green Lakes is approximately 6 miles of stress-free, flat hiking into the Three Sisters Wilderness via either Todd Trail Number 34 or Green Lakes Trail. The area sits in the shadows of South Sister and Broken Top and is home to 28 free campsites, making it a great spot to set up camp and prepare for the strenuous hike ahead.

From Green Lakes, the trail doesn’t remain flat for long; the unnamed trail that leads up the east side of South Sister is a jagged, rocky path that has been carved out of the rugged, steep mountainside. This trail has not been managed by anything other than occasional foot traffic, which makes it easy to lose in the landscape if you’re not careful. Along with this, the ice and snow of Lewis Glacier have overwhelmed the trail in spots, requiring you to either carefully forge your own route around the glacier, minding the crumbling rock that covers the mountain, or go over it and try your best not to slip. Crampons will make this part of the hike quite a bit easier. For these reasons it is also recommended that you bring a GPS, because you’ll be able to keep track of the path if you lose it in the mountain’s terrain.

Once you merge with South Sister Climber Trail, it is just over a mile of blustery, calf-burning climbing to the summit. Make sure you pack some warm clothes. The wintry temperatures and screaming winds at 10,318 feet will make the incredible vistas tough to enjoy if you’re wearing the same outfit you were when you set out.

Logistics + Planning

Preferable season(s)




Parking Pass

NW Forest Pass


Great view. Empty in spots.


Poor trail conditions. Crowded in spots.

Trailhead Elevation

6,316.00 ft (1,925.12 m)


Backcountry camping
Historically significant
Rock climbing
Bird watching
Big vistas
Geologically significant



Took this route from Green Lakes in July 2018. Was planning on meeting up with the hikers trail near Moraine Lake as I was on the loop trail heading clockwise. As I had my morning snack at Green Lakes, this trail popped up on my GPS, but it wasn’t on my map. What a spectacular alternate! Even with a full pack, worth every second. The views back to Broken Top were surreal.
I took this route down after hiking the main climbers trail up; must have been in 2011, September. Awesome route that gives you a completely different perspective than the main climber route! Highly recommended, probably better later summer as the snow fields have melted and there is less traversing of such (unless as noted, crampons).
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