We enjoyed the Black Hills more than Yellowstone. Yellowstone is a fantastic place but it is such a large area you need to drive several hours a day everyday to see all the highlights the park has to offer and everything is run by the parks dept and is kinda expensive. The Black Hills has a lot more to offer. State parks, national monuments and parks, Reptile Gardens and Bear Country and this list goes on and on. If you can while in the Black Hills think about hiking up to the top of Harney Peak. It is the highest peak east of the Rockies and the view is incredible. Have Fun!!