Airmap reports a lot of the Santa Monica Mountains are now a National Park and a No-Fly Zone forever. That mountain range used to be the Santa Monica Mountains Recreational Area and some of the parks within it were CA State Parks where you could fly, but no more becoming a National Park. Much lies along Mulholland Hwy., Beverley Hills area, etc. all the way east to the 101 from Point Mugu Naval Air Station south of Ventura to the west, and a lot of Malibu beaches as well. Seems it is in transition now and who knows where it will end up.
Fwiw, the Supt. of this new Nat. Park designated some area around the 118 in Simi Valley called Paramount Studio Ranch okay for drones as it had some flying field there to the north so he left it alone.
Flying areas in LA got a lot smaller as did some beaches.