Six Rivers National Forest is a U.S. National Forest located in the northwestern corner of California. It was established on June 3, 1947 by U.S. President Harry S. Truman from portions of Klamath, Siskiyou and Trinity National Forests. Its over one million acres (4,000 km2) of land contain a variety of ecosystems and 137,000 acres (550 km2) of old growth forest. It lies in parts of four counties; in descending order of forestland area they are Del Norte, Humboldt, Trinity, and Siskiyou counties. Six Rivers is named after the six major rivers that pass near or through the forest and include:
- the Eel River
- the Van Duzen River (tributary of the Eel)
- the Klamath River
- the Trinity River (tributary of the Klamath)
- the Mad River
- the Smith River
The forest has 366 miles (589 km) of wild and scenic rivers, six distinct botanical areas, and public-use areas for camping, hiking, and fishing. The northernmost section of the forest is known as the Smith River National Recreation Area. Forest headquarters are located in Eureka, California. There are local ranger district offices in Bridgeville, Gasquet, Orleans, and Willow Creek.