Foothills Fault Zone

The Foothills Fault Zone is about 320 km long, is the dominant structural feature of the western Sierra Nevada.

USGS Information on the Foothills Fault System

The Foothill Fault System is one of the reasons that, after the 1975 Oroville earthquake the Auburn Dam, a concrete arched dam which was under construction at the time, was never completed due to seismic risk.

Last estimated rupture was in the late Quaternary period.