Desolation Wilderness, Protected natural area in El Dorado County, United States.

Desolation Wilderness is a 63,960-acre (258.8 km2) federally protected wilderness in El Dorado County, California, within Eldorado National Forest and the Lake Tahoe Basin Management Unit. The Sierra Nevada crest runs through it just west of Lake Tahoe. Bare grey granite forms sloping ledges and blocky cliff faces, with a white waterfall dropping between dark rock walls; scattered conifers and shrubs grow from crevices. Pyramid Peak, at 9,985 feet (3,043 m), is the highest point.

Washoe communities traveled these mountains before the region became a Forest Reserve in the late 1800s. The valley was classified as a primitive area in 1931 and later gained its current wilderness status.

The name comes from the barren granite that led 19th-century cattlemen to call it "Devil's Valley"; the Washoe used these mountains before them. Today the wilderness is split into 45 permit zones, and the Tahoe Rim Trail and Pacific Crest Trail cross it, so through-hikers and day visitors share the same rocky paths.

Visitors need permits for both day trips and overnight stays, with a quota system in place from late May through September. Trails can remain under snow in early summer, while high-altitude weather shifts rapidly and requires preparation.

Lake Aloha sits among broad granite slabs and forms a branching water system of shallow bays and small islands. Horsetail Falls drops nearly 500 feet (150 meters) over steep rock walls in multiple sections, drawing attention especially in spring.