We camped at a handful of camp sites this summer. Richardson Grove State Park was the first one we went to. It was within walking (only 10 min drive) of the Eel and Russian Rivers. The park is in the middle of beautiful redwoods and the scenery is amazing.
The weather was a little muggy in August but the sites were beautiful! Flushing toilets and hot showers were available. We definitely plan on going back to this one. One tip is to not go the first weekend in August as there is a massive reggae concert on the river across from the campground that goes on every year.