The San Andreas mostly runs down the east side of the Coast Range south of Salinas down to Maricopa. Then it turns east. However, the Transverse Range, mostly the San Gabriel and San Bernardino mountains, but also including the San Jacinto Mountains, is also on the western side of the San Andreas fault in Southern California. These are not mere scrapings of sediment, but metamorphic granite. These must have been part of the North American Plate.
LA is in much more danger .
LA, Whittier, Pomona, San push Bernardino, Riverside, Lancaster, Newport, Victorville, Malibu, Santa Monica, Inglewood, Long Beach, Palos Verdes, Santa Monica Bay, and look at the mountains, the San Gabriel's, Santa Ana's, San Jacinto's, San Bernardino's, and Santa Monica's. Thank you, M'am. It's curious that nobody has used seismic tomography to either find that descending plate or prove that it has melted away. It's obvious to anyone who has ever seen Ansel Adams's famous picture of the eastern scarp of the Sierra Nevada's at dawn that there must be one hell of a fault in the Owens Valley. We know that Yosemite's Half Dome and El Capitan are plutons.