Hi all - I'm planning on traveling to the area with my girls (17 & 11). We will be driving from Illinois (13 hrs) and staying for 4 nights. Can someone help with a somewhat aggressive itinerary? We will be arriving around dinnertime on a Wedneday night and leaving sometime on Sunday. I'd like to see as much as possible. Obviously Mt. Rushmore & Crazy Horse are on the list...but what else are the must do's ? I'm not familar with the area at all.