Campgrounds in Marin County, CA

[oregontocal]

I'm leaving here and meeting a friend who lives in San Francisco. After three months in the middle of nowhere, I'm pretty hesitant to drive my little RV pulling my pickup through the Streets of San Francisco. So, I've decided to find a decent campground (that's campground, not RV Resort) somewhere in Marin County, fairly close to the ferry landing in Vallejo, I believe it is. Does anyone have any recommendations? I don't want to pay a lot, and really don't need all kinds of hookups. All I need is a place to stay the night that's close enough.

Chris