We arrived at about noon, and in the guide book it says 4 hours minimum time to see most. The book was wrong, or maybe I just read and take pictures of so many things. We need another full day to see the rest, and we will be coming back before we leave the area. It starts about 650 million years ago when Nevada, and Las Vegas was under water. Climate change has evaporated the water, and we now have a desert. There were no humans back then to start climate change, and it is a natural action on our wonderful planet.