Having gone through the same exercise a few years ago, I would recommend you head towards Tehama or Napa. There are lots of pigs in those areas now, and ranchers and vineyards are pretty eager to get rid of them (keep in mind that it may take a few visits before they consider you worthy). Many of the areas I used to hunt are closed to vehicle traffic now, which is a plus in some ways, not so much in others.
A few tips:
* Take a few weekends and go knock on ranch doors and just ask if they know anyone in the area who might be having trouble with pigs. Offer a business card with all of your contact info on it (including an address) so you come across as serious and not a drive-by. If they offer a name, ask if you can use their name when you meet the other person (country folk are kind of sticklers about some things).
* Go talk to feed store owners, they will likely have some information for you on who to talk to. Put up a few fliers in those feed stores if the owner says it sounds like a good idea.
* Spend some time in the small local diners ranchers stop in at. Chat up the servers, see if they have heard of anyone who is seeing damage from pigs. Leave them a few cards, and don't forget to tip them.
* These same techniques work for finding good coyote and ground squirrel shooting areas, too.
* Once you find a rancher willing to let you hunt, offer to do some work for the privilege of access (fix fences, do truck repair if you know how, patch feed tanks, fill holes in the roads, etc). Of course, offer some of your game if you are successful, but most could get meat themselves pretty easily if they wanted it.