Hells Canyon Wilderness is a 9,951-acre protected area in central Arizona, about 25 miles northwest of Phoenix, in the Hieroglyphic Mountains across parts of Maricopa and southeastern Yavapai counties. Its rugged desert mountains, enclosed flats, and ring of peaks around Burro Flats give the interior a notably isolated character. The landscape is largely Sonoran Desert shrubland, with saguaro and barrel cactus, paloverde, ocotillo, and desert grasses. It is used for hiking, rock climbing, wildlife watching, and camping. On Earth Day 2008, The Wilderness Land Trust bought a 640-acre inholding that included Hells Canyon itself, a step toward making the wilderness entirely publicly owned.