Overview
South Sister is the most accessible high volcano summit in Oregon, rising from the Deschutes National Forest. At 10,358 feet, it's the state's third-tallest peak (behind Mount Hood and Mount Jefferson), and you can reach the top without ropes, crampons, or technical climbing skills. That doesn't mean it's easy. This is a 12-mile round trip with 4,900 feet of elevation gain, mostly on loose volcanic rock above treeline. It's a long, hard day hike that rewards you with one of the best summit views in the Pacific Northwest.
The trail starts at Devils Lake Trailhead on Cascade Lakes Highway (Highway 46), about 27 miles west of Bend. From the summit, you can see Mount Hood, Mount Jefferson, Three Fingered Jack, Mount Washington, Broken Top, North and Middle Sister, and on exceptionally clear days, Mount Rainier to the north and Mount Shasta to the south. That's over 300 miles of Cascade Range laid out in front of you. On the same trip, many hikers combine the South Sister approach with an evening at Green Lakes, which shares the same trailhead access corridor and sits in the basin directly below the summit route.
The Route
Miles 0 to 1.5: Forest and meadow. The trail leaves Devils Lake Trailhead and climbs through mountain hemlock forest. The grade is moderate here, a warm-up for what comes later. You'll pass through open meadows where wildflowers bloom in late July and early August.
Miles 1.5 to 3: Moraine Lake. The trail steepens as it approaches Moraine Lake at about 7,000 feet. This is a good spot for a quick water break and to assess conditions. If the terrain above looks icy or if thunderstorms are building, this is your turnaround point. Beyond Moraine Lake, there's no shelter from lightning.
Miles 3 to 4.5: The scree grind. Above Moraine Lake, treeline fades and the trail enters the volcanic scree zone. The surface is loose cinders and pumice. For every two steps forward, you slide back one. This is the section that breaks people. The trail is marked by rock cairns, but in fog or snow it can be hard to follow. Stay on the established route to avoid the steepest and loosest sections.
Miles 4.5 to 5.5: Lewis Glacier and upper slopes. You'll pass the remnants of Lewis Glacier on your left (south side). It's shrunk considerably in recent decades, but crevasses can still be present. Stay on the trail and don't walk on the glacier unless you have proper equipment and experience. The route continues up the south ridge on increasingly solid rock.
Miles 5.5 to 6: The crater and summit. The final push brings you to the crater rim. Teardrop Pool sits in the crater at about 10,200 feet, a small, stunning lake that's usually ice-covered until August. Walk along the rim to the true summit on the north side, marked by a USGS benchmark. Take your time here. You earned this view.
Descent: Return the same way. The loose scree that punished your legs on the way up becomes a fast (if sloppy) descent. Many hikers find the downhill harder on the knees than the climb was on the lungs. Trekking poles make a real difference on this trail.
Permit Requirements
A Central Cascades Wilderness Permit is required for all hikers, day and overnight (see our camping permit guide for general permit tips). The permit system is managed through Recreation.gov. Day-use permits cost $1 per person per day.
South Sister is one of the most popular wilderness destinations in Oregon, and permits sell out quickly. Here's how the system works:
- Advance reservations open in the spring for the entire summer season. Snag one as soon as they become available.
- Day-of permits are released at 7 AM Pacific, two days before the trip date (for example, permits for Saturday are released Thursday morning). Set an alarm and be ready to go. These sell out in minutes for South Sister on summer weekends.
- Shoulder season: Before and after the permitted season (roughly mid-June through mid-October), no permit is required. However, conditions during shoulder season can include significant snow, ice, and route-finding challenges.
You'll also need a Northwest Forest Pass ($5/day or $30/year) or America the Beautiful Pass for parking at Devils Lake Trailhead.
When to Hike
Mid-July through September is the reliable window. Snow typically clears from the route by mid-July in a normal year, though snowfields can linger into August after heavy winters. September often brings the most stable weather and the fewest crowds.
Start early. This is not optional. Begin hiking by 5 to 6 AM for three reasons: (1) the parking lot fills before dawn on summer weekends, (2) afternoon thunderstorms build over the Cascades regularly in July and August, and (3) you want to be off the exposed upper mountain by early afternoon. Being above treeline during a lightning storm is genuinely dangerous.
Time budget: Most hikers take 8 to 12 hours round trip. Fit, experienced hikers may finish in 6 to 7 hours. Don't cut your timeline short. Allow extra time for rest, photos, and the inevitable slow sections on the scree.
What to Bring
This is a serious mountain hike, not a trail jog. Pack accordingly.
- Water: Minimum 3 liters per person. There's no reliable water source above Moraine Lake, and the dry volcanic terrain and high-altitude sun will dehydrate you faster than you expect.
- Layers: Temperatures can be 30 to 40 degrees cooler at the summit than in Bend. Wind chill at the top can push conditions well below freezing, even in August. Bring a wind shell, insulating layer, and gloves.
- Sun protection: Sunscreen (SPF 50+), sunglasses, and a hat. You'll be above treeline and exposed for hours. The UV intensity at 10,000 feet is no joke.
- Trekking poles: Highly recommended for the scree sections on both the ascent and descent. They save your knees and improve stability on the loose rock.
- Map and navigation: Carry a physical map or downloaded offline map. Cell service is nonexistent at the trailhead and on the mountain. The route is generally well-cairned, but visibility can drop to near zero in fog or storms.
- Food: High-calorie snacks and a real lunch. You're burning 3,000 to 4,000 calories on this hike.
- First aid kit: Blisters are common, and the loose rock can cause minor scrapes and ankle tweaks.
Common Mistakes
Starting too late. If you're leaving the trailhead at 9 AM, you're probably going to have a bad time. You'll be grinding through the scree in the hottest part of the day, and you'll be exposed on the upper mountain when thunderstorms are most likely.
Underestimating the scree. The loose cinder section from miles 3 to 4.5 is demoralizing. It's not technically difficult, just relentless. Many people turn around here. If you've trained on steep terrain and know what 4,900 feet of gain feels like, you'll be fine. If your longest hike to date is 5 miles and 1,000 feet, consider working up to this one.
Not enough water. Three liters is a minimum. On a hot day, you might want 4. Dehydration at altitude leads to headaches, nausea, and poor decision-making, which is dangerous above treeline.
Skipping the permit. Rangers patrol this trail regularly. Getting caught without a permit means a fine, and more importantly, the permit system exists to protect the wilderness from overuse. Plan ahead and get your permit. Recreation.gov releases day-of permits at 7 AM Pacific; have the app ready on the morning of your planned hike date.
Trailhead Access
Devils Lake Trailhead is located on the Cascade Lakes Highway (Highway 46), approximately 27 miles west of Bend. The highway is a well-maintained two-lane road, but it closes for winter (typically November through late May). Check road conditions with the ODOT TripCheck website before driving out.
The trailhead has a paved parking lot, vault toilets, and an information kiosk. The lot holds about 30 cars, and on summer weekends it overflows onto the road shoulder. Arrive before 6 AM to get a spot. There's no shuttle service, so carpooling helps.
After the Hike
Your legs will be trashed. Bend has no shortage of post-hike options: breweries (Deschutes Brewery, Boneyard Beer, Crux Fermentation Project), restaurants, and the Deschutes River for a cold soak. If you're camping, Devils Lake Campground is right at the trailhead (free, first-come-first-served, 10 sites). Todd Lake Campground is a few minutes north on Highway 46 and offers a quieter alternative.
South Sister is one of those hikes that reminds you why you train, why you wake up in the dark, and why you haul 3 liters of water up a mountain. The summit payoff is worth every step on that loose volcanic rock. For a shorter and quieter introduction to the same volcanic landscape before committing to the full summit, the Proxy Falls loop on Highway 242 shows off the Three Sisters Wilderness geology in under 2 miles.