I live in SoCal and here are the tracks I've ridden (not all are in CA):
1.)Willow Springs International Raceway: Big Track and Streets of Willow
2.) Auto Club Speedway (fomerly California Speedway): 2.3 Mile AMA Superbike track
3.) Spring Mountain Motorsports Ranch (Pahrump, NV)
4.) Miller Motorsports Park (East course and Full track configurations) MY FAVORITE!!
5.) Reno/Fernley-I LOVE THE BIG TRACK CONFIGURATION/layout, I just don't care for the MASSIVE bumps in the braking zones and in the apices (plural for apex? LOL!!).
Tracks I plan on tackling in the next year and a half:
5.) Buttonwillow Raceway (sometime in late 2010 early 2011).
6.) Chuckwalla Raceway (April 17, 2010 with fastrackriders dot com)
7.) Infineon Raceway-AMA configuration (2011 Trackday)
8.) Thunderhill Raceway (HIGHLY LOOKING FORWARD TO THIS ONE-I may be there this SUMMER 2010!).
9.) Las Vegas Motor Speedway (WERA West configuration).
BTW-all of these tracks are anywhere between a 1/2 hour to 10 hour driving distance-in relation to where I live! A trackday/race at any of these tracks can easily be done in one weekend.