English: The walls of Black Canyon of the Gunnison National Park in western Colorado are so deep they can be overwhelming. The canyons carved by millions of years by the Gunnison River feature some of the steepest cliffs, oldest rock, and craggiest spires on the continent. Some of the crevices along the 12 miles of the canyon are twice as high as the Empire State Building and so narrow that regions of the canyon on see about 33 minutes of direct sunlight per day.