Two billion years of geological evidence of the earth's history is exposed in the canyon's rock walls, more than can be observed anywhere else in the world. Travelling The canyon's length requires a river journey of 277 miles, through canyons varying in distance from less than a half mile to more than eighteen miles apart, and through depths reaching nearly 600 feet. Early visitors named many of the large buttes after ancient gods. Jupiter, Juno, Apollo, Venus, Vishnu, Deva, Shiva and Brahma have temples here, while Vulcan and Wotan have thrones named in their honor. The Paiute Indians believed the canyon had been created by the god Tavwoats to separate the world of the living from the lands beyond death. Havasupai and Hulapai Indians believed the river was the runoff from an earth-covering flood, much like the one Noah experienced.