How to Hike South Sister: Oregon’s Third Tallest Mountain

Hiking South Sister is a bucket-list adventure for outdoor enthusiasts in Oregon. As the state’s third-tallest peak at 10,358 feet, this challenging trail rewards hikers with breathtaking views of the Cascade Range, alpine lakes, and a volcanic summit unlike any other. The trek is strenuous but those who make the climb are treated to one of the most stunning panoramas in the Pacific Northwest!

The South Sister hike is one of Oregon’s most iconic summit treks, leading to the third-highest peak in the state at 10,358 feet. This challenging out-and-back trail spans approximately 12 miles round-trip and features a demanding 4,900 feet of elevation gain, making it a strenuous but rewarding climb.

The hike begins at Devils Lake Trailhead, located along Cascade Lakes Scenic Byway, and winds through a forest before emerging into an exposed alpine landscape. As you ascend, you’ll pass Moraine Lake and Teardrop Pool (Oregon’s highest lake), navigate steep volcanic scree, and ultimately reach the summit, where panoramic views stretch across the Cascade Range.

On a clear day, you can see nearly all of Central Oregon’s iconic peaks including Middle and North Sister, Broken Top, Mount Washington, Three Fingered Jack, Mount Jefferson, and even Mount Hood.

Hiking South Sister is more than just summiting Oregon’s third-tallest mountain—it’s a chance to experience a geologically active landscape up close. As you trek through one of the most densely populated volcanic centers in the world, you’ll encounter eight glaciers including Prouty, Lewis, Clark, Lost Creek, and Eugene Glaciers—one of which is the largest in the state.

This hike is unique because it offers non-technical climbers the rare opportunity to see some of Oregon’s few remaining glaciers up close.

Due to the trail’s difficulty, exposure, and unpredictable mountain weather, proper preparation is essential. Hikers should be ready for a long day on the trail, bring plenty of water, and start early to avoid hiking in the dark.

If you’re up for the challenge, the South Sister hike offers one of the most rewarding summit experiences in the Pacific Northwest! Here’s everything you need to know before hitting the trail.

Best time to hike the South Sister Trail

The best time to hike the South Sister Trail is typically from late June to mid-September, when the trail is mostly snow-free, and the weather is more predictable. During these months, the conditions are ideal for summit attempts, with warmer temperatures, clear skies, and minimal snow coverage. This is the peak hiking season so expect more people on the trail.

Keep in mind late summer (August and early September) brings an increased risk of forest fires in the region, which can significantly reduce visibility and hinder the stunning views from along the trail and at the summit.

If you’re looking for a quieter experience, early or late in the season (June or September) can be less crowded, though there may be snow patches on the trail. Late fall and winter hikes are not recommended due to the snow and ice conditions, making the trail much more challenging and dangerous, even for experienced hikers.

No matter when you’re planning to summit, be prepared for rapidly changing mountain weather, and always check the forecast for South Sister before heading out, as conditions at higher elevations can be quite different from the trailhead.

How to hike the South Sister Trail

With the increasing popularity of the Three Sisters Wilderness, this trail sees around 400 hikers per day. Because of this, as of May 2021, a day-use or overnight permit is required for many trails in the area, including this one—so be sure to plan ahead and secure a permit before your hike!

To start this hike, you’ll need to park at the Devils Lake Trailhead which is located along Cascade Lakes Scenic Byway.

We started our hike much later than planned—our ambitious goal was to be on the trail by 7am, but in reality, it was closer to 10am 😬 (maybe even later).

In our defense, we spent the morning filming an intro for a Youtube video of this hike back at Sparks Lake, where we had camped the night before. Plus, after a surprisingly cold and restless night in the tent, getting an early start was easier said than done.

By the time we arrived at Devils Lake, the parking lot was completely packed! Luckily, just as we pulled in, someone was leaving, and we snagged a spot. We grabbed our backpacks and hit the trail as quickly as possible.

From the trailhead parking lot, you’ll need to cross the Cascade Lakes Scenic Byway to reach the official start of the trail—be sure to watch for traffic. The trail begins as a flat and easy walk. However, after crossing a small footbridge over Tyee Creek, the ascent begins.

This climb starts off as a gradual but steady incline, the kind that really makes your calves burn. Some hikers prefer these long, less steep climbs, while others would rather tackle a short, steep ascent to get it over with—I definitely fall into the latter group.

After what feels like an eternity of slow climbing, a flat sandy plateau finally comes into view—hallelujah! Unfortunately though, from here on out, there’s no shade.

Enjoy this flat stretch while you can because things are about to get much harder, but for now, you’ll be hiking over gentle rolling hills.

At this point along the trail, South Sister comes into full view, and you truly begin to grasp just how massive this mountain is. It dominates the skyline, and although it looks deceptively close, trust me—it’s still a long way to go before you even reach the base.

About halfway across the sandy plateau, you’ll come to a stunning overlook of Moraine Lake. To the left of the lake, you’ll see Broken Top, and to the right, Mt. Bachelor. This is a great spot to pause for a quick snack break, giving you the perfect excuse to soak in the breathtaking views a little longer.

You may notice campsites along Moraine Lake’s shoreline. If you’re planning to tackle South Sister as an overnight hike, this is a scenic spot to set up camp. Plus, having the lake to rinse off after a grueling climb would be a refreshing bonus.

After a short break, we pressed on. The plateau eventually meets the base of the mountain, and from here, the real challenge begins. The trail steepens dramatically, and you’ll need to navigate loose volcanic rock as you ascend.

This is the second hardest section of the hike. From this point, you still have about two miles to go, with roughly 2,000 feet of elevation gain—so pace yourself, because things are about to get tough!

Once you’ve climbed 2,000 feet up the steep, rocky terrain, you’ll reach a saddle where Teardrop Pool—Oregon’s highest lake—sits just below South Sister’s summit. Above it looms Lewis Glacier, one of the mountain’s eight glaciers.

This “false summit” is a popular resting point, where many hikers pause for a break or lunch before taking on the final, grueling ascent.

For some hikers, seeing the final stretch of trail climbing steeply to the volcano’s crater is enough to call it a day—and that’s totally okay. There’s no shame in turning back.

By this point, Jamie was exhausted and told me he wouldn’t be going any further. I was a little disappointed but understood. Still, I debated with myself—was it worth continuing? It wasn’t just the difficulty; it was already 3:30 p.m. and there was still another mile to go with 1,300 feet of elevation gain. If I forged ahead, we would undoubtedly be hiking back in the dark.

At some point, every hiker has to weigh the risks when pushing toward a summit. Since we were no strangers to night hiking, I decided that as long as we made it back to the sandy plateau before nightfall, it was an acceptable risk, so I decided to press on alone.

The final mile from Teardrop Pool to the crater rim is short but painfully steep. The trail climbs through loose volcanic scree, where tiny, marble-sized rocks make every step feel like two forward and one back. Being the middle of August, the sun was intense, making every step an effort.

About a quarter of the way up, I was shocked to see Jamie had changed his mind. He had caught up to me and decided to join my quest for the summit after all—hooray, someone to share in the misery with again!

After what felt like an eternity, we finally reached the crater rim. But again, we were hit with another disappointment—this still wasn’t the true summit.

The official endpoint is on the far side of the crater, and while it seems like a short distance away, crossing the half-mile-wide crater isn’t as easy as it looks because a large snowfield sits in the middle. And at this point, exhaustion had fully set in. Jamie decided this time it really was as far as he would go.

By now, there were only two other hikers reaching the summit at the same time as us. Of the two, one of them decided he’d join Jamie in calling it quits too, while the other guy was stubborn like me and determined to see the journey to its end.

Even though it was getting late, I knew I had to continue. I left my backpack with Jamie and hurried toward the true summit. Fortunately, the route around the crater wasn’t too difficult, with only a few minor scrambles.

Along the way, I was rewarded with amazing views of Broken Top and Central Oregon stretching eastward. And after hiking another 20 or 30 minutes—I finally reached the highest point of South Sister!

The view from the official end of the South Sister Trail is nothing short of spectacular. Looking north, peaks stretched as far as the eye could see. Middle Sister and North Sister, already impressive from below, were absolutely majestic from this angle.

The drop-off from the crater’s edge was dizzying, but despite my fear of heights, I couldn’t resist peeking over.

After soaking in the moment and snapping a few photos, I made my way back to Jamie as quickly as possible. I didn’t tell him right away just how incredible the views were—I didn’t want him to regret stopping at the rim.

But if you’re reading this and debating whether to continue all the way around the summit crater, trust me, if you’ve made it to the top, push through to the true summit! The views are dramatically different from the north side, and they are absolutely worth making the extra effort.

The descent was long and grueling, and as expected, we ended up hiking back in the dark for a solid two hours. Thankfully, we made it back to the sandy plateau before nightfall, which was crucial for safety.

Under the nearly full moon, the night hike was actually quite beautiful and peaceful. The trail was illuminated most of the way, except for the last two miles through the forest before reaching the parking lot.

As I mentioned earlier, we almost always start our hikes later in the morning, so hiking in the dark is nothing new to us. Walking through the forest under the stars with noone else but us on the trail, actually turned out to be a perfect ending to an unforgettable hike.

Tips for hiking the South Sister Trail

• Start early. Be sure to start your hike to South Sister’s summit early in the morning unless you are prepared to hike back in the dark. This is a long and strenuous trek, requiring between six and nine hours to complete.

• Pack a flashlight in case you find yourself hiking back in the dark. It’s always best to be prepared, as conditions can be unpredictable.

• Bring plenty of water—at least three liters—as this is a full-day hike. While there are water sources along the trail, you’ll need to filter any water before drinking. Consider carrying water purification tablets or a water-filtering bottle.

• Pack plenty of food, as this is a grueling hike—not just in mileage, but also in vertical gain. It’s always wise to bring extra snacks in case you spend more time on the trail than expected.

• Wear sunscreen. This trail is mostly exposed so don’t forget to bring sunscreen. I recommend the Sun Bum SPF 30 Sunscreen Spray with vitamin E—it’s reef-friendly, and free of octinoxate and oxybenzone (harmful chemicals).

• Bring lightweight layers in case the weather changes unexpectedly. It’s also much cooler at the summit and on the return hike.

• Be aware of trail conditions. The earlier in the season you hike this trail, the more likely you are to encounter snow. By late August, forest fires are common and can obstruct the views from the summit.

• Check the weather. Check the weather forecast here before your South Sister hike. Bad weather can be dangerous at the summit and may also obscure the stunning views.

• Hiking Permits are required. Day use permits are required to hike the South Sister Trail between 15th June and 15th October. Learn more here.

• A pass is required to park at the trailhead. A Northwest Forest Pass is required to park at the trailhead, or you can purchase a $5 day pass on-site. The Northwest Forest Pass costs $30 and grants access to all national forests in Oregon and Washington. If you have a National Parks Annual Pass, it can also be used for parking at this trailhead.

Discover more hidden gems near South Sister

Todd Lake is a beautiful alpine lake situated near the base of Mount Bachelor and the Three Sister Mountains. A hike around this lake offers stunning views of the surrounding peaks and forests.

Devils Lake is a stunning alpine lake situated near the base of South Sister Mountain. This lake is known for its clear, turquoise-colored waters and is a popular spot for standup paddleboarding and camping.

Where to stay near South Sister Mountain

Soda Creek Campground is a small campground tucked into the forest just off Cascade Lakes Scenic Byway near Sparks Lake. Set near the base of South Sister and Broken Top, it is the perfect base camp for hikers wanting to summit nearby mountains and explore the surrounding lakes.

Elk Lake Resort, located along Cascade Lakes Highway offers a variety of lodging options to suit different preferences. Guests can choose from rustic cabins, RV, or tent sites, all set against the picturesque backdrop of Elk Lake.

Riverhouse Lodge in Bend, Oregon, is a premier resort nestled along the scenic Deschutes River. The lodge offers guest rooms featuring private patios or balconies with river views, fireplaces, and upscale amenities. Amenities include both indoor and outdoor heated pools, a hot tub, and a restaurant serving Pacific Northwest cuisine.

Where is the South Sister Trailhead?

The South Sister Trailhead is located in the Cascade Mountains of Central Oregon, within the Deschutes National Forest. From Bend, take Cascade Lakes Scenic Byway (Highway 46) west for about 28 miles. It’s just a short drive past the Mount Bachelor Ski Area.

Look for the Devils Lake Campground sign along the highway—parking for the trailhead is directly across from the campground. There’s a designated parking area and a vault toilet available, but spots can fill up quickly on summer weekends and holidays, so it’s a good idea to arrive early.

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