Trinity Alps Wilderness, Designated wilderness area in the Klamath Mountains, California, United States

Trinity Alps Wilderness covers 537,357 acres between Eureka and Redding, administered by the U.S. Forest Service across the Shasta-Trinity, Klamath and Six Rivers National Forests. Its eastern half holds granite peaks called the White Trinities and reddish ultramafic peaks called the Red Trinities, while forested mountains to the west form the Green Trinities. Thompson Peak, at 9,001 feet, is the highest point, and glacial cirques cut the high country.

The Trinity Alps Wilderness was designated by the California Wilderness Act of 1984, which folded the earlier Salmon-Trinity Alps Primitive Area into the National Wilderness Preservation System. The U.S. Forest Service administers it across the Shasta-Trinity, Klamath and Six Rivers National Forests. About 4,000 acres of private inholdings once lay inside the boundary; purchases by the Wilderness Land Trust have cut that figure by more than 40 percent.

The name "Trinity" comes from Trinity County and the Trinity River, not from the peaks themselves; the granite core is called the White Trinities, the reddish ultramafic southeast the Red Trinities, and the wooded west the Green Trinities. Historic gold mining structures and relics stand in various parts of the wilderness, and gold panning still draws experienced amateurs.

Most trails are in poor condition and hard to follow, so map and compass skills are essential. The paved road north from Junction City leads to the Canyon Creek trail, the most popular entry; other routes from the north and west are only seasonally accessible by car. Bears are common, so carry a bear bag or canister.

The region harbors rare conifers like Brewer spruce, typically found further south in the Sierra Nevada. This unusual combination emerges from its location between mountains and the Pacific coast, bringing different ecosystems into contact.