Since I was about 3, my family has gone to Joes Valley Reservoir for an extended family reunion! We tend to reserve the entire lower loop for a week in August. It's a bit of a downhill walk to the lake, but worth it given that there are plenty of fish and crawdads to catch for a big fish-fry! 

There are toilets and picnic tables, and the roads have been paved in recent years. The best part about the campground is its ability to host a large group. The area is spread out yet open enough to feel like everyone has their own space and still together as a group. So, if you're wanting to plan a family trip, this may be where you want to go! 

It is a bit noisy, however. Everyone has 4-wheelers and most people bring RV's with generators... so expect some noise, lol.