Desert View Tower

At the east end of the Grand Canyon National Park, this tower provides a huge view of the canyon. The Colorado River comes south from Utah and makes a turn to the west here. Because of the bend, the view of the canyon is wider than elsewhere in the park.

Scientists argue about how the canyon formed. Some say that it's been only 6 million years, others say more like 17 or 20 million. Some think that the ancestral Colorado flowed up into Utah and then west to reach the ocean at Monterey Bay, which was then located close to where Los Angeles is now. If so, then the San Andreas Fault may have moved it north while also creating the route that the river now takes to the Gulf of Calfornia (or Sea of Cortez).

Along the way, the Fault may also have had a hand in creating one of the Creationist arguments about the age of the earth. The contention is that the Colorado doesn't have enough delta to have removed all the rock from the Grand Canyon and the rest of its drainage system. There are several answers to this, including the fact that much of the rock may not have reached the sea, being dropped before then to build up the area south of the Salton Sea and the fact that much of the rock removed was limestone and other rock that dissolves in water. Another piece, though, is that part of the delta itself has been moving northward along the Pacific tectonic plate, resulting in a "delta" that's much more elongated than is usual for a river system.