Merced Pass Trail

Merced Pass Trail is a backcountry route in Yosemite National Park that drops from the Mono Meadow area into the Illilouette Creek Basin and links toward Lower and Upper Merced Pass lakes, with continuation options for the Red Peak Pass trail system.

A common access for starting the trail run is the Mono Meadow Trailhead along Glacier Point Road. From there, the route heads southeast into the wilderness, getting farther from roads and sound as it pushes deeper into the Illilouette Creek corridor.

The character of the hike is described as remote and wilderness-focused: you’ll be moving through forested stretches and basin wetlands while the route threads toward the high country near the Merced Pass lakes.

Distance and effort depend on your turnaround. A full run to Lower Merced Pass Lake is listed as strenuous at about 12.0 miles one-way; shorter day objectives into the Illilouette Creek basin are often in the ~3.5 to 6 mile range.

Elevation profile is a big part of the work. Expect net loss heading toward the basin and a corresponding climb on the way back, with enough demand that planning for route-finding and navigation matters.

This trail also functions as an access artery for longer multi-day backpacking. From the Merced Pass Trail corridor, you can branch toward Red Peak Pass, Ottoway Lakes, or make connections toward the Chain Lakes area via Chiquito Pass.

Backcountry overnight travel requires a Yosemite Wilderness Permit. If you’re camping, plan for permit logistics before you go and time your trip around seasonal conditions—snowpack can persist into early summer at higher elevations.

Water is available in the region via streams such as Illilouette Creek, but you should carry and use proper filtration and treat flows as seasonal rather than guaranteed.

More information: Red Peak : Climbing, Hiking & Mountaineering - SummitPost.org, What is the name of the trail in the middle of this picture? : r/Yosemi...