The San Pablo Fault is a fault in

northern California Northern California (colloquially known as NorCal) is a geographic and cultural region that generally comprises the northern portion of the U.S. state of California. Spanning the state's northernmost 48 counties, its main population centers incl ...

.Point Molate Casino EIR, Volume I, 2009, accessed May 25, 2010
It is an offshoot of the Hayward Fault. It formed the Potrero Hills in

Richmond, California Richmond is a city in western Contra Costa County, California, United States. The city was municipal corporation, incorporated on August 7, 1905, and has a Richmond, California City Council, city council.

Notes

Seismic faults of California Geology of Alameda County, California Geology of Contra Costa County, California Geography of Richmond, California {{ContraCostaCountyCA-geo-stub