240 Million Years
The Canyons of the Colorado and Dirty Devil Rivers meet just below Cataract Canyon (to the right/ north), under the red rock walls of Wingate and Kayenta sandstone, the knobs and fins of Navajo sandstone, and the southernmost peaks of the Henry Mountains (aka “Little Rockies”), Mount Ellsworth (l, 8,235 ft/ 2510 m) and Mount Holmes (r, 7998 ft/ 2438 m). This slice of Earth’s crust shows off layers deposited over a 240 million year period by shallow oceans, windblown desert sands, and rivers. The dominant bright white sandstone in the bottom layer is White Rim sandstone. A storm had moved through the night before, but hadn’t finished dropping a bit of snow in the Henrys and periodic rain across the canyons.