So here we are, the canyon has disappeared as the edge of the Hogback blends in with the basin far away.

The Hogback is the Chinle layer, 500 feet and about 25 million years later than the basin below, in the late Triassic. The plesiosaurs and icthyosaurs grew gigantic and frolliced (or terrorized, take your pick) in the depths of the sea, while this region was a peaceful land of meandering rivers, shallow lakes, and swamps, punctuated by the croaking of frogs, the sploosh of the first turtles diving into the water as the fleet-footed early dinosaurs ran into view.

That is, if you can fathom that water ever came to this arid place.