Desolation Wilderness is a federally protected high-country area in California’s Sierra Nevada west of Lake Tahoe, distinguished by bare granite, glacial basins, scattered lakes, and thinning forests near the tree line. Used by the Washoe before European settlement and later grazed as cattle country, it gained federal protection by the late 19th century, became the Desolation Valley Primitive Area in 1931, and was designated Desolation Wilderness in 1969 under the Wilderness Act of 1964. It includes the Crystal Range, Pyramid Peak, Lake Aloha, and Horsetail Falls, supports varied alpine wildlife and vegetation, and is heavily visited for backpacking while managed with permits and seasonal quotas.