From the trailhead the first 1 1/2 miles follows the route noted in the Summit Lake Trail description. Approximately 1 mile beyond the Pacific Crest/Summit Lake Trail intersection is the start of the Warren Lake Trail (14E24). This trail begins with an ascent through a pleasant alpine forest consisting of lodgepole pine, red fir, and mountain hemlock. Beyond the forested area the trail crosses a saddle (8570 feet in elevation) with spectacular views.

From this ridge the trail begins a 3 1/2 mile descent into the valley alongside the northeastern slopes of Castle Peak and Basin Peak. In this area the trail traverses a unique glaciated basin which offers a sense of backcountry remoteness rarely found in the Tahoe Sierra. Watch for the huge, dark-layered volcanic rocks and the underlying granite rocks. There are also many creeks to cross, with spectacular displays of subalpine wildflowers.

After reaching another saddle the trail begins a quick descent of some 1000 feet and winds steeply down toward Warren Lake.

On the western side of the lake there are a number of inviting campsites.

To reach the trailhead, take the Castle Peak Area/Boreal Ridge Road exit, off of Interstate 80, which is immediately west of the highway's Donner Summit Roadside Rest Area. On the south side of the highway there is a sign reading: Tahoe National Forest Trailhead Donner Summit Pacific Crest Trail Follow the directions on the sign for .4 mile to the trailhead. This trailhead provides access to the following trails: Pacific Crest Trail, north and south; Glacier Meadow Loop (15E32); Summit Lake (15E09); Warren Lake (14E24); and Sand Ridge Lake (14E11).

This hike to Warren Lake can be challenging.