4. Black Canyon of the Gunnison National Park, Colorado
The canyon of the very narrow Black Canyon of the Gunnison National Park in Colorado is 2,722 feet deep at its deepest point at Warner Point. The Painted Wall, the tallest vertical wall in the entire state of Colorado reaches a height of 2,250 feet. Most rock climbing takes place on the North and South Chasm walls of Black Canyon, with an average canyon depth of a dizzying 1,820 feet.