The Coyote Creek segment of the San Jacinto Fault network, the most active fault network in Southern California, erupted at 12:30 p.m. Saturday,
Nov. 18 and was felt throughout much of the county. The epicenter of the 3.9 magnitude quake was 5.9 miles east of Borrego Springs.

Scientists closely monitor this fault because of its potential to produce a major quake in the 6 to 7 magnitude range. Dr. Frank Vernon, research seismologist U.C. San Diego, Scripps Institution of Oceanography, is working with Idyllwild Water District to install seismic monitors in the Idyllwild area. Vernon noted that the Hill has not had a major quake in nearly 200 years and is overdue for one.