JT,
From down Oceanside way, you might try contacting Dave Sabon or Charles Carter. They are both members here on StuntHanger, but I don't know how often they check in.
Up toward LA, not sure of any CL flying in Orange county. Closer to LA you've got a great field at Whittier Narrows, which is a county park. They lease the land from the Army Corps of Engineers. The clubs that fly there are the Knights of the Round Circle, the SoCal Speed Flyers, and the remnants of the SoCal Air Racers (SCAR). Their website is:
http://kotrc.org/On the other side of LA, you have the Valley Circle Burners out in the San Fernando valley, flying at Apollo XI Field at Sepulveda Basin. This is also an Army Corps of Engineers property leased to LA for recreation. We have two active and a couple of reserve circles there, all paved.
There was talk of trying to get a circle back at the Mile Square park in OC, but at this point, it is still talk and probably a lot of hurdles to jump before it might happen, if ever.
I think there are some combat guys who used to fly in the Fallbrook area. That actually might be closest for you? I know that Darrell Albert CD'd a few of these, so maybe he would have some info. Not sure if I have a current phone number for him. I'll look.
Dave Hull
Valley Circle Burners