Here is the link to my trip report on my August 2017 trip to the Badlands, Black Hills, and watching the eclipse from Alliance, Nebraska.
https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/29487108.cfmIt was somewhat of a whirlwind tour and I plan on going back again. Rushmore in only worth a couple of your hours, there is much more to see, a lot I missed.
I included links in my trip report so that may prove useful. These links may also prove useful in planning.
http://www.blackhillsbadlands.com/http://www.blackhillsbadlands.com/things-to-dohttp://www.blackhillsbadlands.com/plan-your-triphttps://www.travelsouthdakota.com/trip-ideas/itineraries/road-trip-south-dakotas-badlands-and-black-hillsTime constraints prevented me from spending more time there, I planned my arrival two days after the end of Sturgis after being told on a discussion forum by a Sturgis native that the bikers clear out rapidly at the end of the gathering, and the lady at the Spearfish Campground also told me this on the phone. When I arrived in Spearfish, the campground was only about half full, no bikers in sight. The other end of my time limit was being in Alliance on the next Monday for the Eclipse. It was a good trip and I enjoyed the road trip out and back also.
In December, there was a 54,000 acre fire covering the southern part of Custer State Park, and part of Wind Cave Nat Park, so the area around the wildlife loop will look very much different for a time to come.
Charles