The Grand Canyon was created by the Colorado River, and is still a work in progress. The river has cut down through millions of years of sedimentary rocks, all the way down to Pre-Cambrian rock which is over 1 billion years old. The views from the viewpoints are sublime and the Colorado River can be seen from some of them, including Lipan Point and Pima Point. The canyon is a mile deep and is 18 miles wide at its widest point.