High Quality Content by WIKIPEDIA articles! The Fort Tejon earthquake occurred at about 8:20 am (Pacific time) on January 9, 1857 in central and Southern California with an estimated moment magnitude of 7.9. It ruptured the southern part of the San Andreas Fault for a length of about 225 miles (350 kilometers), between Parkfield and Wrightwood. The earthquake was felt throughout much of California, as far north as the city of Marysville and as far south as the mouth of the Colorado River at the Gulf of California in Mexico, and as far east as Las Vegas, Nevada.