Must see/do's
Wall Drug
Badlands
Prairie Dog Observation Point.
All of the above are right by each other.
Other must do's
Pioneer Auto Museum in Murdo SD.
16A southeast out of mount rushmore for the curves then into Custer Nat Park for buffalo.
Spearfish Canyon Rd.
Deadwood. I would try and make it your base of operations if you can once you get out there.
Other good ideas.
antique archaeology near Davenport, the American Pickers show.
Sturgis was ok, worth a drive through to say you been there but I would not stay there or plan on any time there.
Honestly, Devils Tower was a let down. Not worth the effort imho.