On the border, IA and IL
Nice campground, with lots of sites, $10 or $20 with electric. Lots of trails, and the Mississippi River is across the road. If you come this way, be sure to check out the historic towns of Mount Carroll and Galena. I'd give this 5 stars, but the bathrooms are a bit dirty and have quite a few cobwebs. Otherwise it's well maintained, plenty of private sites, and quiet.
Month of VisitJuly