Loma Prieta Periodic Comet Machholz 1 96P/Machholz on May 12, 1986. The first official West Coast Messier marathon was conducted from this site in March 1979. The epicenter of the 1989 Loma Prieta earthquake was near the mountain. The mountain was the longtime site for the transmitter tower of San Jose television station KNTV (from 1955 to 2005). It moved its transmitter northwest to San Bruno Mountain in September 2005, after it became the Bay Area's NBC affiliate. Loma Prieta is the tallest peak in the Santa Cruz Mountains and it is common to see snow on the mountain during the winter.
1989 Loma Prieta earthquake for the northern San Andreas Fault segment, the San Francisco Peninsula segment, and a portion of that segment which was referred to as the southern Santa Cruz Mountains segment. The thirty year probability for one or more M7 earthquakes in the study area was given as 50%, but because of a lack of information and low confidence, a 30% probability was assigned to the Southern Santa Cruz Mountains segment. Two moderate shocks, referred to as the Lake Elsman earthquakes by the USGS, occurred in the Santa Cruz Mountains region in June 1988 and again in August 1989. Following each event,