If you intend to visit CSP, a couple of things to know. Its a South Dakota State Park, so it requires an entrance fee (not much) instead of the National Parks Pass.
And if you're going to drive the wildlife loop (you should) take some carrots. There are a lot of wild burros living there. They're descendants of the burros the prospectors owned during the gold rush. The park rangers prefer that you don't feed them, but know that the burros can insist. One burro stands in the middle of the road (I assume they take turns) while the others go from car to car, begging. I have pictures somewhere but can't find them. And watch your fingers. The Burros have lousy aim.