Yeah, the Arroyo Grande campground in the Los Padres. But it's about 45 minutes from there to the West Side. The drive over from the East Side is about the same. But, you could hike over from the East Side. Two flat miles from the Chalone Creek Trailhead, right to the Balconies Caves. Very pretty hike too.
Or, Kev, you could do us all a favor. Run for Congress or the Senate. Then, when you win, use your position to make the Park Service open up a West Side campground. I'd vote for you!