Three Sisters Loop: Alder Creek to Obsidian Zone

The Three Sisters Wilderness loop is an epic 50-mile trek through the diverse landscape of the Cascade Range in central Oregon. The trail loops around three of Oregon’s prettiest peaks (South Sister, Middle Sister, and North Sister), and features incredibly scenic landscapes of lava rock, glaciers, volcanoes, lakes, and meadows filled with wildflowers.

This post details our third day of our five day backpacking trip on the Three Sisters Loop. Check out the links below for detailed information on the other sections of the trail. If you want to hike this trail yourself, check out our ultimate planning guide to backpacking the Three Sisters Loop for info on permits, wilderness regulations, and sample itineraries.

Day 1: Devils Lake Trailhead to Green Lakes (7.7 miles)

Day 2: Green Lakes to Alder Creek (12.5 miles)

Day 3: Alder Creek to the southern border of the Obsidian Limited Entry Zone (12.2 miles)

Day 4: Obsidian Zone to Mesa Creek (8.2 miles)

Day 5: Mesa Creek to Devils Lake Trailhead (6.3 miles)

Map and Elevation Profile for Alder Creek to Obsidian Zone

Three Sisters Backpacking Trail Guide: Day 3

We woke up with the sun and were able to watch the sun rise over miles of burn zone to the east. After experiencing unbearably hot temperatures with little shade the day before we were eager to start hiking in the cool morning. We hiked out of our camp at Alder Creek and hiked through about three more miles of burned forest. The heat was starting creep in, even though it was only 7am.

Shortly after clearing the burn zone we started climbing toward Scott Pass. The trail switchbacked through an old growth forest and large red rock boulders. As we continued to climb we were treated to some views to the east.

When we came to the junction with Scott Pass Trail 4068, the views opened up and we the entire valley lay beneath us. We made a left on Scott Pass Trail and in a short two miles we were reached South Mathieu Lake and the junction with the PCT (Pacific Crest Trail).

We stopped to filter water at South Mathieu, since we knew it was going to be our last water source for quite some time. Camping at South and North Mathieu Lakes is restricted to designated sites. South Mathieu is closest to the trail and it has three campsites. North Mathieu is further off trail. Both lakes are on the PCT, and the campsites fill up quickly.

After connecting with the PCT at Matthieu Lake the landscape turns into large lava fields with massive cinder cone mountains. The views were so amazing that I barely noticed the steep climb. To my left North Sister was rising from behind Yapoah Crater. And to my right miles of lava fields stretched out before me with views of Mount Washington and the buttes in the distance.

As we approached the junction with the Scott Trail 3531 we got a break from the relentless climbing and took a break in a shady part of the meadow. While we snacked we chatted with some NOBOs (PCT hikers heading northbound) on the busy trail.

We hit the trail feeling refreshed and ready for another long climb. After passing through the meadow the trail begins the ascent to Opie Dilldock pass. Partway up the mountain there is a small alpine meadow with a hidden spring that isn’t marked on any map. It may dry up in the late-summer, but in early August it was our last water source until the obsidian zone.

We continued climbing and soon the trees were replaced with lava fields. Summiting Opie Dilldock pass and walking along the ridgeline of a massive volcanic lava field was the highlight of the trip. Descending the switchbacks was a bit tricky. With every step the large chunks of rock would slide beneath our feet- I was glad that I was going down this and not the other way around!

At Sawyer Bar the lava fields gave way to a lush forest filled with ferns and wildflowers. You can see the line where water once flowed and created this sharp contrast in the landscape. Just past Sawyer Bar we entered the Obsidian Limited Entry Area. If you want to camp in the Obsidian Limited Entry Zone you need to reserve a permit in advance through Recreation.gov. If you do not have a permit for the obsidian zone you are allowed to walk through the area, but you must remain on the PCT (Pacific Crest Trail) and you cannot stop to camp. Current regulations issue permits that allow 40 people a day to camp in the obsidian zone.

We wandered slowly through the Obsidian Zone and hung out near the creek for a while. The Obsidian cliffs were formed from one of Middle Sister’s volcanic eruptions. And while the obsidian isn’t as extensive as the obsidian fields in Newberry Volcanic National Monument, it is still pretty cool.  We filled up all of our water bottles, knowing that we’d be camping at a dry camp tonight and our water needed to last through the night and into the morning.

As we exited the Obisidian Zone we managed to find a campsite high above the trail, in the trees, with incredible views of the entire Three Sisters range. Unfortunately, the mosquitoes found this campsite too and that evening they came out in full force. I probably walked an extra mile around camp trying to dodge mosquitoes while watching the alpenglow light up the sisters.

Podcast about Backpacking Three Sisters Wilderness

I was honored to talk with Jeremy from the Trails Worth Hiking podcast about my Three Sisters backpacking trip. Check out the podcast for a deep dive into the history and geology of the trail as well as a day-by-day discussion of what to expect on the trail.

The Trailhead

From Bend, Oregon the Devil's Lake trailhead is approximately 29 miles west on Cascade Lakes Highway (46). Turn left at the sign for Devil's Lake trailhead. Parking at the Devils Lake trailhead costs $5 per day. Forest Passes and interagency passes are accepted as well. Check out this USFS guide for a detailed list of costs and accepted parking permits.

The Route

Pick-up the trail behind the bathrooms and walk a short distance before crossing a road and meeting up with the South Sister Climber Trail No. 36. Follow the trail for two miles and make a right at the junction with Moraine Lake to start your counter-clockwise adventure around the Three Sisters.

After you pass Moraine lake, follow signs for the Green Lakes trailhead. When you reach a junction with Soda Creek make a left to continue toward Green Lakes. Stay on the Green Lakes Trail for 21.5 miles.

Make a left at the junction with the Scott Pass Trail and follow Scott Pass for 2 miles until you reach the PCT (Pacific Crest Trail). Make a left to take the PCT south and stay on the PCT for 17.8 miles.

Make a left onto the Leconte Crater Trail. Stay on the Leconte Crater Trail for 1.3 miles.

If you would like to summit South Sister follow signs for the Moraine Lakes Trail and follow the trail for 1.6 miles until you reach the South Sister Climber Trail (make a left to summit, and make a right to return to the trailhead).

If you aren't summiting South Sister, continue on the Leconte Crater Trail until you reach the Wickiup Plains Trail. Make a left at the junction and follow the Wickiup Plains Trail for 2 miles back to the trailhead.

Other Details

Dogs allowed on leash. But the volcanic rock can be very hard on paws, please think twice before bringing your dog on this entire loop.

Pit toilets are available at the Devils Lake Trailhead. No other services are available.

Trailhead parking fills up quickly. Arrive early if you want a parking spot.

Like all outdoor pursuits, hiking can be dangerous. It is up to you to assess your fitness level and education yourself about any potential dangers. While I try to regularly update these hiking guides, you should always research trail conditions before heading out.

Being prepared means arriving at the trailhead with water and some basic provisions. Each and every time I hit the trail I bring a backpack with more water than I think I need, a small first aid kit, and a snack. I also share my itinerary and plans with friends or family and I carry an InReach so I can summon help if needed. If you want to know what I carry in my pack during day hikes check out my blog post about essential gear for day hikers.

Stay safe, enjoy the trail, and soak up the magic of nature!

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