Be aware that Wind Cave NP is more than the cave. We camp there every fall to listen to the elk bugle. You can see as much wildlife here as at Yellowstone, except for the wolves, bear and moose. We used to go to Yellowstone every fall, but we were seeing more elk at Wind Cave NP than Yellowstone NP. The bison here are also pure bison, as in no cattle dna in them. Just across the fence in Custer SP, the bison have cattle dna, so they take keeping them separate very seriously.
Oh yeah, the gold mine in Lead is now an underground science lab, but the tour won't get you underground. Just so you know, the visitor center is under construction.
