The Trinity Alps Wilderness is a 525,627-acre (212,714 ha) designated wilderness located in northern California, roughly between Eureka and Redding. It is jointly administered by Shasta-Trinity, Klamath, and Six Rivers National Forests. About 4,623 acres (1,871 ha) are administered by the Bureau of Land Management. The wilderness is located in the Salmon and Scott Mountains, subranges of the Klamath Mountains region. The high, granitic and ultramafic peaks of the eastern half of the wilderness area are known as the Trinity Alps. Granite peaks at the core of the area are known as the White Trinities, reddish ultramafic peaks in the southeast are known as the Red Trinities, and the forested mountains in the western half of the wilderness are known as the Green Trinities.

The Shasta–Trinity National Forest is a federally designated forest in northern California, United States. It is the largest National Forest in California and is managed by the U.S. Forest Service. The 2,210,485 acre 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).