Geochemical map of the Mount Eddy and Castle Crags Roadless Areas, Shasta, Siskiyou, and Trinity counties, California

The Mount Eddy and Castle , Crags Roadless Areas occupy 9,600 acres (39 km²) and 3,300 acres (13 km²), respectively, in Shasta, Siskiyou, and Trinity Counties, Calif., approximately 8 mi (13 km) west of the towns of Mount Shasta City and Dunsmuir (fig. 1). Access is provided by secondary roads and trails from Interstate Highway 5, which passes through Mount Shasta City and Dunsmuir. The areas are located in rugged terrane in the easternmost part of the Klamath Mountains where altitudes range from about 2,500 ft (7.62 m) in the southern Castle Crags area to 9,025 ft (2,751 m) on Mount Eddy. Manzanita and other brush are ubiquitous at lower elevations whereas vegetation is lacking at higher elevations except for occasional gnarled conifers and ground-level plants.