Charles Mill Lake Park in Mifflin Ohio. A great place to enjoy the day use RV life boondocking area. Also a good spot to use a dump station if you need one of those for your RV.
Swimming fishing and boat rentals are available here. Camping is available in to Campground and starts about $35 a night for sites without hookups. Obviously not a good boondocking place for camping but is a great place for day use.