Black Canyon of the Gunnison National Park is in western Colorado. The park contains 12 miles of the 48-mile long Black Canyon of the Gunnison River. The national park itself contains the deepest and most dramatic section of the canyon, but the canyon continues upstream into Curecanti National Recreation Area and downstream into Gunnison Gorge National Conservation Area. The canyon's name owes itself to the fact that parts of the gorge only receive 33 minutes of sunlight a day, causing the rocky walls to appear black. At its narrowest point the canyon is only 40 ft wide at the river, The Gunnison River drops an average of 34 feet per mile through the entire canyon, making it the 5th steepest mountain descent in North America. By comparison, the Colorado River drops an average of 7.5 feet per mile through the Grand Canyon. The greatest descent of the Gunnison River occurs within the park at Chasm View dropping 240 feet per mile. Roads and trails along the north and south rims have views of the Black Canyon’s dramatic drops such as this picture at Painted Wall. Painted Wall is the highest cliff in Colorado, bordering the far side of the river; a 2,250-foot wall of rock about half a mile across. This marks the end of the most enclosed part of Black Canyon since downstream the sides, although becoming even higher, are noticeably less steep, and more overgrown.