Supporting a large population of salmon and trout, the Chetco's water is of very high quality. The watershed is home to many other species, including several that are endemic to the Siskiyou Mountains area. The northernmost grove of Redwoods—the tallest trees on Earth—grow in the southern region of the Chetco's drainage basin. In total, the river is home to over 200 species of animals, and 97 percent of the watershed is forested.