Spent three nights at Mollidgewock State Park recently. Absolutely beautiful positioning next to a river. Clean sites - many covered in grass with wildflowers which were stunning. Ours had gravel which I ended up being pleased about after finding a tick crawling on our tent. The owner/manager was extremely friendly and helpful. The pit toilet was very clean, well-ventilated, and stocked with toilet paper and hand sanitizer. The main bummer was the proximity to a road -- the road noise was pretty significant (you could also hear ATVs behind the road). I think it would have been less noisy further in the campground (higher-numbered sites) where the river noises were louder. I would definitely recommend a campsite further in (avoid sites #1-5 ish that are directly next to the road - car lights will shine in your tent at night as cars drive in). This wasn't a huge deal, but the sites further down were more private and further from the driveway. 

Errol does not have much in the way of grocery stores and there are apparently two restaurants but we didn't check those out. Excellent outdoor gear/supply store! 

They rent kayaks/canoes on the property which was fun (saw a bald eagle). Awesome hikes nearby - we did Dunn Falls in Maine. 

Overall, great campground but would probably choose a different site next time as I prefer a more private set up.