We did that trip in 2009. We left Friday evening and drove to South Bend, IN area and then got up early and breezed through Chicago Saturday morning. Frankly, there is not much between Ohio and the Badlands. We stopped at Wall Drug but found it to mostly be a tourist trap. The Badlands were beautiful for a drive through. We stayed one night in the Black Hills/ Mount Rushmore and wish we had planned more time. Devils Tower was a nice stop for lunch and a short hike. We stayed on the east side of Glacier in the KOA and had very high wind events two nights in a row. We also travelled up into the Canadian side and above to Banff. All in all a lot of driving but very well worth it.