Hearthstone is better than the one in town, but the entrance is on a pretty fast stretch of road, so do be careful pulling in and out.
As for the Catskills, I have stayed at just one campground while journeying to rallies in PA or other destinations south and west, and that is Little Pond. It is on a back road in the middle of some beautiful country, but driving an RV on the road to get there wouldn't be my idea of a good time by any means. The campsite itself is clean and very nice, however, and very quiet. My buddy and I called ahead since we weren't going to be able to arrive before the office closed at 9 PM, and they were kind enough to leave some firewood for us and let us pay when we left in the morning. MOst of these smaller DEC campgrounds are run by a caretaker who lives either onsite or nearby, and they are run more like a mom and pop operation. Just rustic and quiet enough, but with clean showers and bathrooms.
If you are traveling through PA, I can also recommend the Steel Steeds campground, which we used as our Triumph Classic Triples rally home last summer. Very laid back and comfortable, with enough cleanliness to be tolerable, but no strict stuff. (It is run by a guy and reflects our male standards of cleanliness

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