Those ads have been on TV in CA for years. They have even got the CA Milk Board or whoever produces them sued by PETA which claims the cows aren’t as happy as advertised. Probably they are right about the ones living in Fresno, but the ones I have seen grazing on green hillsides in Marin look very happy indeed.
Since the type of cheese isn’t specified, I suggest you look carefully at the labels of cheeses in your neighborhood grocery. There may weell be some from CA. Certainly here in CA, locally made cheeses of all varieties are common–and not only ones from cow’s milk: Chanel goat cheeses are de riguer as well. Not only are there CA cheese producers making huge quantities for the mass market, there are plenty of extremely good artisanal producers like Chanel and, here in the Bay Area, Cow Girl Creamery: http://www.cowgirlcreamery.com/ .