Out in the desert northeast of San Diego, the San Andreas fault runs along the base of the Mecca Hills where a series of canyons have been carved out of sandstone that formed when this whole area was an ancient sea floor. Just like rings on a tree, the seasons can be counted by looking at the layers of rock. If you look even closer you can find fossilized seashells and other evidence that this was once in fact a much wetter place.

Tags: Hiking, Canyoneering, Sonora Desert