Mammoth Crest and Duck Pass Loop

The trail typically starts near the Mammoth Lakes basin. A common access point is near Coldwater Campground, which offers parking. Given the popularity of the area, especially during peak season, it's advisable to arrive early to secure a spot. Shuttles may also operate in the Mammoth Lakes area, providing alternative transportation to trailheads.

The ideal time to hike this loop is generally from late June or early July through September or early October, once the snow has melted from the higher elevations and passes like Duck Pass. During this period, you'll experience more stable weather, accessible trails, and vibrant wildflowers. Always check current trail conditions and weather forecasts before heading out.

Yes, dogs are generally allowed on this trail, as it is located within the John Muir Wilderness. However, they must be kept on a leash at all times to protect wildlife and ensure a pleasant experience for all hikers. Please remember to pack out all pet waste.

While there is no entrance fee for the John Muir Wilderness itself, wilderness permits are required for all overnight stays. If you plan to complete the Mammoth Crest and Duck Pass Loop as a day hike, a permit is not typically needed. However, regulations can change, so it's always best to check with the local ranger station (Inyo National Forest) for the most current information before your trip.

Expect a diverse and challenging terrain. The trail begins with an immediate ascent, often through forests, before opening up to exposed ridgelines. You'll encounter steep sections, switchbacks, and areas with loose rock, sand, and scree, particularly along the Mammoth Crest. The descent from Duck Pass also features steep, rocky switchbacks. Sturdy hiking boots with good ankle support are highly recommended.

This loop offers breathtaking scenery throughout. You'll enjoy panoramic views of the Mammoth Lakes basin, including Lake George & Lake Mary Overview, and distant peaks like Banner Peak and Mount Ritter from the Mammoth Crest. The trail also passes numerous pristine alpine lakes such as Barney Lake, Skelton Lake, and Gentian Meadow Pond, each offering picturesque stopping points. Keep an eye out for unique red rock formations, evidence of the active Long Valley Caldera.

This loop is considered a strenuous and challenging hike, covering over 20 kilometers (12.5 miles) with significant elevation gain. It is not recommended for beginners or families with young children due to its length, difficulty, and varied terrain. Hikers should have a good level of fitness and prior experience with long-distance, high-altitude trails.

Yes, the route utilizes and intersects with several other trails. Notable sections include the Mammoth Crest Trail, Emerald Lake Trail, and the Duck Pass Trail. You'll also encounter portions of the Woods Lakes Trail, Sky Meadows Trail, and Deer Creek Trail, among others, as you navigate the loop.

Given the trail's length, elevation, and exposure, essential items include plenty of water (at least 3-4 liters), high-energy snacks, sun protection (hat, sunglasses, sunscreen), layers of clothing for changing weather, a map and compass or GPS device, a first-aid kit, and sturdy hiking boots. Trekking poles can also be very helpful for the steep ascents and descents.

The John Muir Wilderness is home to diverse wildlife. You might spot various bird species, marmots, pikas, and ground squirrels. Larger mammals like deer are also present, and if you're very lucky, you might catch a glimpse of a black bear (always practice bear safety). Remember to observe wildlife from a distance and never feed animals.