Dave investigates the idea that the boundary between the North American and Pacific tectonic plates may be in the process of "stepping" eastward from the San Andreas Fault to the so called "Walker Lane." He visits with Nevada Bureau of Mines and Geology tectonics expert Jim Faulds, who is one of the leading proponents of the new theory. We take a virtual geologic field trip from the Gulf of California, up through the Eastern California Shear Zone (where the July 4-5 Ridgecrest earthquakes rocked