Don't split at visalia. I'd say a good splitting area would be just south of bakersfield at the mountains. There's hardly anything out there and more than likely no paintballers so you won't have the effects of splitting at Visalia.
I live 7 miles from Visalia and if you split there, they'll be norcal and i'll be socal and it would be more of a pain. There's quite a few teams between Tulare and Visalia also (like atleast 3 or 4) and splitting it will make it much harder to keep track of local events.
I agree with a lot of the previous posters and say leave california as a whole. It's easier that way.