Twenty miles long, 400 feet deep, and ΒΌ-mile wide, the canyon was carved by Walnut Creek. The creek winds through entrenched meanders, testimony to downcutting sometime in the past several million years. The canyon rim elevation is 6,690 ft; the canyon’s floor is 350 ft lower. The Sinagua people settled here between 1125 and 1250 CE. They build stone walls to enclose natural recesses in the Permian Kaibab Limestone as habitation space; the ceilings are coated with soot from fires that largely died out around 1250 CE. Cropping out below the Kaibab Limestone is the rubbly Toroweap Formation and the cliff-forming Coconino Sandstone. The latter displays massive cross beds that formed in the Permian when an eolian sand sea (think Sahara Desert) blanketed much of what is now northern Arizona.
Image with yellow arrows courtesy of the US Geological Survey. Yellow arrows pinpoint some of the ruins in natural recesses of the Kaibab Limestone.
