Overview
The Duck Pass Trail is one of the best day hikes in the Mammoth Lakes area, and it's a strong contender for the best moderate-hard trail in all of Inyo National Forest. The 9.6-mile out-and-back climbs from Coldwater Campground (8,900 feet) through a chain of alpine lakes to Duck Pass at 10,797 feet, gaining about 2,500 feet of elevation along the way. It regularly appears in recommendations for the best hikes near Los Angeles as a top-tier Eastern Sierra day trip. Each lake is more scenic than the last, and the view from the pass, looking down into the Purple Lake basin and across the John Muir Wilderness, is worth every switchback.
The trail follows Mammoth Creek through forest and meadow, passes Arrowhead Lake and Skelton Lake in quick succession, then climbs to Barney Lake in a granite bowl below the pass. The final push from Barney Lake to Duck Pass is the steepest section: about 700 feet of gain in a mile on exposed switchbacks. But at the top, the Sierra unfolds in every direction.
This is also one of the most popular entry points for backpackers heading into the John Muir Wilderness. The Pacific Crest Trail and John Muir Trail pass through the Purple Lake area just beyond the pass, connecting Duck Pass to a vast network of backcountry routes. For overnight trips, start with the national forest camping permit guide to understand the quota system and self-issue process that applies here.
The Route
Miles 0 to 1.5: Coldwater Campground to Arrowhead Lake (9,700 ft). The trail starts from the Duck Pass Trailhead at Coldwater Campground in the Mammoth Lakes Basin. The first stretch climbs moderately through a lodgepole pine and red fir forest, crossing Mammoth Creek on a footbridge. The grade is steady but not steep. At about 1.5 miles, Arrowhead Lake appears on your left, a small, clear lake tucked among granite boulders and conifers. It's a pleasant spot for a quick break, but the better lakes are ahead.
Miles 1.5 to 2.3: Arrowhead Lake to Skelton Lake (9,900 ft). The trail continues climbing gently past Arrowhead Lake and reaches Skelton Lake less than a mile farther. Skelton is larger, deeper, and more photogenic than Arrowhead, sitting in a rocky basin with scattered whitebark pines along its shore. The turquoise water is striking against the granite. Anglers work the shoreline here for brook trout.
Miles 2.3 to 3.5: Skelton Lake to Barney Lake (10,200 ft). Beyond Skelton Lake, the trail climbs more steeply through thinning forest and across a series of granite benches. Meadows open up with views of the Mammoth Crest to the east. The trail crosses several small streams (reliable through August, potentially dry by late September) before reaching Barney Lake at about 10,200 feet. Barney Lake is the highlight for many hikers: a deep alpine lake surrounded by sheer granite walls, with the Duck Pass headwall rising directly above. The lake makes a natural turnaround point for hikers who want a shorter day (7 miles round trip, 1,300 feet gain from this point back to the trailhead).
Miles 3.5 to 4.8: Barney Lake to Duck Pass (10,797 ft). The final stretch is the toughest. The trail switchbacks up the headwall above Barney Lake, gaining about 600 feet in a mile. The terrain is exposed and rocky, with loose sections near the top. Snow lingers on these switchbacks into July in many years. As you crest the pass, the view opens west into the John Muir Wilderness: Purple Lake sits below, and the Silver Divide stretches across the horizon. On a clear day, you can see deep into the backcountry toward the Mono Creek drainage and the peaks beyond.
Descent: Return the same way. The descent goes quickly, typically taking about an hour less than the climb. Watch your footing on the loose sections above Barney Lake.
Permit Requirements
A wilderness permit is required for this trail. Day hikers and overnight backpackers both need permits, and the Duck Pass trailhead operates under a daily quota system.
- Day-hike permits: Available through Recreation.gov. Cost is $5 per person. Reserve in advance when possible, as the Duck Pass quota fills on summer weekends.
- Overnight permits: Also $5 per person through Recreation.gov. Reservations open six months in advance on a rolling basis. The Duck Pass entry is popular with backpackers heading to Purple Lake and beyond, so overnight permits for Friday and Saturday entries book early.
- Walk-in permits: A portion of the daily quota is held for walk-ins, available at the Mammoth Lakes Welcome Center on Main Street (Highway 203) in Mammoth Lakes. Pick them up the day before or the morning of your hike. Arrive when the office opens for the best selection.
No additional parking pass is required at the Coldwater Campground trailhead, but a wilderness permit must be visible in your vehicle if you're parked overnight.
When to Hike
Mid-July through September is the reliable window. Snow on the Duck Pass switchbacks typically melts out by mid-July, though it can persist longer after heavy winters. The trail below Barney Lake is usually clear by early July.
Late July and August offer the most reliable conditions: snow-free trails, running streams, and wildflower displays in the meadows between Skelton Lake and Barney Lake. Afternoon thunderstorms are possible, so start early and plan to be heading down from the pass by early afternoon.
September is outstanding. The mosquitoes have died off, the crowds are thinner, the weather is usually stable, and the aspens along the lower trail begin turning gold. Water sources above Barney Lake may be dry, so carry enough for the full hike.
Early October is possible but risky. Early-season snow can make the pass switchbacks dangerous, and the road to Coldwater Campground may close for the season. Check conditions before committing.
What to Bring
- Water: 2 to 3 liters per person. Streams along the route provide filtered water through August, but the upper section above Barney Lake is dry in late season.
- Layers: The pass is nearly 11,000 feet, and wind can be strong. Bring a wind shell and a warm layer even on summer days. Temperature at the pass can be 20 to 30 degrees cooler than at the trailhead.
- Sun protection: Sunscreen, sunglasses, and a hat. The upper trail is fully exposed.
- Trekking poles: Very helpful on the steep switchbacks above Barney Lake, both up and down.
- Lunch: This is a 5- to 7-hour hike for most people. Bring enough food for a real break at Barney Lake or the pass.
- Camera: The chain of lakes and the view from the pass are exceptional.
- Bug spray: July and early August can bring heavy mosquito activity near the lakes and in the meadow sections. DEET or picaridin recommended.
- Bear canister: Required for all overnight trips in the John Muir Wilderness. Not needed for day hikes, but store all food and scented items properly.
Dogs on the Trail
Dogs are allowed on the Duck Pass Trail and must be kept on leash. The trail is suitable for fit, well-conditioned dogs, but keep a few things in mind. The altitude (starting at 8,900 feet and climbing to nearly 11,000 feet) can affect dogs just as it affects humans. The rocky sections above Barney Lake are rough on paws. Bring extra water for your dog, and watch for signs of overheating or altitude distress (excessive panting, wobbliness, refusal to move). Clean up after your dog and pack out waste.
Common Mistakes
Not budgeting enough time. The trail's 9.6-mile distance and 2,500 feet of gain are moderate on paper, but the altitude makes everything harder. Allow 5 to 7 hours for the round trip, plus time for breaks at the lakes.
Turning around at Arrowhead Lake. Arrowhead is pleasant, but it's a fraction of what this trail offers. If you can make it to Barney Lake (3.5 miles in, 1,300 feet of gain), the scenery improves dramatically. The pass itself is the payoff.
Underestimating the altitude. The trailhead starts at 8,900 feet, higher than many people have ever hiked. If you've just driven up from sea level, your body will feel the difference on the steeper sections. Acclimatize for at least a day in Mammoth Lakes (7,880 feet) before tackling this trail.
Late starts in thunderstorm season. If you're hiking in July or August, be on the trail by 7 AM and plan to clear the pass by 1 PM. Afternoon storms build quickly over the Sierra crest, and the pass is the worst place to be during lightning.
Trailhead Access
The Duck Pass Trailhead is located at Coldwater Campground in the Mammoth Lakes Basin. From the town of Mammoth Lakes, take Lake Mary Road west for about 3.5 miles to the Coldwater Campground turnoff. The trailhead parking lot is at the end of the campground road. It's paved, with vault toilets and a bear-proof dumpster.
The parking lot holds about 40 cars and fills by 8 AM on summer weekends. Arrive early or consider a weekday hike.
Coldwater Campground (77 sites, $26/night) is the most convenient overnight staging area if you want an early start. Reservations through Recreation.gov are recommended for summer dates. The campground has potable water, flush toilets, and bear boxes at each site.
Beyond the Pass
If the day hike to Duck Pass leaves you wanting more, the trail continues into some of the finest backcountry in the Sierra.
Purple Lake sits about 2 miles beyond the pass (roughly 1,000 feet of descent from the pass to the lake). It's a gorgeous alpine lake at 9,900 feet, and campsites along its shore are among the best in the John Muir Wilderness. The Pacific Crest Trail and John Muir Trail pass through here, so you'll share the area with through-hikers in summer.
Connecting to the JMT/PCT: Duck Pass is a popular entry and exit point for John Muir Trail section hikers. From Purple Lake, you can head north toward Red's Meadow (about 8 miles) or south toward Lake Edison (about 15 miles). These connections make Duck Pass a strategic trailhead for longer trips.
The Duck Pass Trail delivers a concentrated version of everything that makes the Eastern Sierra special: alpine lakes, granite walls, a high pass with expansive views, and easy access from a major recreation hub. It's harder than a lakeside stroll but far more accessible than the big peak climbs, making it the ideal choice for hikers who want a full Sierra experience in a single day.
For hikers who want a warm-up or a shorter companion hike, Convict Lake Loop is about 15 miles south: an easy 2.8-mile flat circuit around a glacial lake with big peak views and no permit required. On the longer end of the spectrum, Bishop Pass south of Mammoth offers a similar high-lake-to-high-pass structure with even more dramatic scenery. For the entire Eastern Sierra day hike picture from Bishop to Mammoth, see our Inyo National Forest guide.