Several years ago I had a ridiculous amount of hotel points so we decided to drive out to Colorado to see my DW sister & BIL and use the points for free stays instead of dragging the camper. We did all the touristy stops out there including Sturgis, Deadwood, Mt Rushmore, Custer State Park, Sitting Bull Monument, Etc.
I agree the Badlands are great if you are into that. DW and I enjoyed driving thru and seeing the colors of the rocks and how the shadows changed the looks. We exited the Badlands on some back road (don't recall the route) and were amused at all the dirt roads labeled "1st Ave", "2nd street" etc. We drove for a good 20 min. and not a car in sight (we were there in Nov.). There was a sign on one dirt road indicating an Indian Reservation. I said let's go see so turned off onto the dirt road and headed for this escarpment about 2 miles away. After driving at a very slow speed dodging literally thousands of prairie dog holes and enjoying watching the little rodents looking about we crested the hill and saw...nothing but prairie out to the horizon.
So turning about and heading back to the main highway the 30 min or so drive back we never saw a single vehicle go down the main road Visual for miles on either side of the flat, treeless terrain. You could have had a picnic in the middle of that road without issue. We finally reached the paved road and I stopped and waited. The DW asked what was I waiting on? I said to her, "I'm waiting for you to tell me it's clear on your side".
Fortunately for her we were driving across country so she had a change of clothing in the luggage in the back of the Durango.
