A graphical representation is available from the Northern California Data Center at UC Berkeley. Two of the most important fault systems are the San Andreas Fault system and the Hayward Fault system. The numerous faults in California make it a very seismically active region. A map of seismicity from from 1977-1996 gives a good idea of the number of earthquakes that happen in California. Without doubt, one of the most damaging earthquakes in California's history was the San Francisco earthquake of 1906.
Many sites are available describing the destruction following the earthquake.
The USGS lists it as one of the largest earthquakes ever recorded in the United States . A thorough documentation of the event is available from the Museum of the City of San Francisco . Another major earthquake struck the city in 1989. Information about the 1989 earthquake is also available from the Museum of the City of San Francisco. Because California experiences so many earthquakes, there are numerous resources available on the web detailing California's earthquake history.