We dropped by Hapgood Campground on our way west out of New England. We needed a cheap or free place to sop for one night while it rained and stormed over us.
Hapgood fit just what we were looking for. It’s a National Forest campground so free for us, with certain national park passes (awesome!).

The sites were wooded and relatively private. This was mid-week in July and the camground wasn’t even quarter full. We were able to grab one of the first-come/served sites.
There was a a small pond and beach too. It rained for the 18 hours we were there so, the camp was what we needed, but we didn’t explore much.