The Shasta–Trinity National Forest is a federally designated forest in northern California, USA. It is the largest National Forest in California and is managed by the U.S. Forest Service. The 2,210,485 acre (894,552 Ha) forest encompasses five wilderness areas, hundreds of mountain lakes and 6,278 miles (10,103 km) of streams and rivers. Major features include Shasta Lake, the largest man-made lake in California and Mount Shasta, elevation 14,179 feet (4,322 m). In descending order of land area, the forest is located in parts of Trinity, Shasta, Siskiyou, Tehama, Modoc and Humboldt counties.