need advice on State parks within 3 to 4 hrs of central Oh

We like Delaware and Alum Creek SP's, to me the best campgrounds in the system.

This might be a bit far for you (5 hours or so from Columbus), but Allegheny NF has some excellent campgrounds around the reservoir. Red Bridge, Buckaloons, Willow Bay, Kiasutha. Some sites are FHU, some electric only, some non-electric. Size of rig is no issue at any of them, some nice private sites.