I am volunteering at Custer State Park for the summer. There are many very good camp sites within the park and west of the park in Custer City, Hill City etc. Heartland RV Park is a park that is east of the park at the intersection of Hwy 79 south from Rapid City and Hwy 36 the east entrance to the park. I did not stay there but did stop to fill my propane tanks. The park staff was very friendly and the campgrounds were very clean. The sites were wide with grass between each site. If you are looking for a spot to stay and visit the Black Hills area, Custer, Mt. Rushmore etc. you may want to check out Heartland RV Park. There is a Pilot/Flying J and a Conoco station at the intersection nearby.