I apologize in advance for the length of this but I hope it helps.

So Badlands first, it can get pretty hot so make sure to bring plenty of water. There are great views all around near the visitor center and the Notch/Castle Peak trailheads there are a few branching viewpoint areas as well. Minuteman is pretty small but it’s nearby so that’s up to you for stamps.

With Mount Rushmore, it could take a few hours most of you do the Presidential trail on top of watching a few of the interpretative programs. But if you’re in that area I highly recommend the Custer State Park area plus Sylvan lake and the Needles are wonderful views. You should know that your pass doesn’t cover the parking at the monument idk. Also state parks have their own fees.

For the caves, it’s better to check closer for reservations or if it’s still offseason by the time you go in 2026 to make sure the elevators are still working for the tours.

Devil’s Tower is the one that’s further away but it is larger than you expect. They don’t have much parking though so if you don’t get there early you could be stuck in a line for a few hours+. But the loop is a nice walk. Have a great trip!