Take a look at Henry Cowell state park- we stayed there at the start of a big camping trip last month. Nice facilities, just outside of Santa Cruz, about 1.5 hours from San Francisco. We also stayed at Samuel P Taylor, has really good spots, if you can get them. Since it is so coveted, you'll have to keep a close eye on reserveamerica.com to get your reservation in asap or see if anyone cancels. That was the only way we got a spot. Try to get a trailer site if you are sleeping in the E, that way you dont get a parking space on a slant.