history. The Fort Tejon earthquake of 1857.

http://www.forttejon.org/historyearthquake.html

"When earthquake scientists, or seismologists, think about great earthquakes in California in historic times, three in particular stand out. The most recent "great" earthquake to strike California was also the most famous: the 1906 " San Francisco" earthquake, which (along with the fires that followed) destroyed much of San Francisco and was felt over most of California. Only thirty-four years earlier, in 1872, Owens Valley in eastern California was rocked by an earthquake that was felt over good portions of both California and Nevada. And the largest earthquake to hit Southern California in historic times occurred on January 9th, 1857, and it came to be known as the great " Fort Tejon" earthquake, although such appellation could be very misleading.

Fort Tejon, in fact, was not the epicenter, nor was it even near the epicenter of the earthquake. Surface rupture originated northwest of Parkfield in Monterey County and propagated southeastward for over 360 km (225 miles) along the San Andreas Fault to the Cajon Pass northwest of San Bernardino. Technically, Parkfield was the epicenter of this earthquake, as it was the origin of the rupture, but most scientists would be more concerned with the extent and location of the entire rupture; Fort Tejon was approximately the midway point of the rupture. The earthquake actually acquired its name because Fort Tejon was the only populated locality near the fault, and naturally, the Fort suffered more damage than the rest of sparsely-populated 1857 Southern California.

In comparison to the other "great" earthquakes of historic times, the 1857 "Fort Tejon" earthquake was significantly larger than the 1872 Owens Valley (estimated magnitude 7.8) quake, and was equally as large as, if not larger than, the 1906 "San Francisco" earthquake (estimated magnitude 7.9-8.0). Estimates for " Fort Tejon" are also in the vicinity of magnitude 8.0. The 1857 and 1906 events were both on the San Andreas Fault, although the 1906 earthquake ruptured the northern segment of the fault, from Hollister (San Benito Co.) northward, for 400 km (250 miles). Duration of shaking, along the fault, for both 1857 and 1906 is estimated to be as long as two minutes."

http://en.wikipedia.org/wiki/Fort_Tejon_earthquake

"The Fort Tejon earthquake occurred at about 8:20 AM (Pacific time) on January 9, 1857. It ruptured the San Andreas Fault for a length of about 350 kilometers (225 miles), between Parkfield and San Bernardino. Displacement along the fault was as much as 9 meters (30 feet) in the Carrizo Plain but less along the Palmdale section of the fault, closest to Los Angeles. The amount of fault slip gives this earthquake a moment magnitude of 7.9, comparable to that of the 1906 San Francisco earthquake. Based on the (uncertain) distribution of foreshocks for this earthquake, it is assumed that the beginning of the fault rupture (the epicenter) was in the area between Parkfield and Cholame, about 60 miles northwest. Nevertheless, it is usually called the "Fort Tejon" earthquake because this was the location of the greatest damage, most of the area being unpopulated at the time."