The Black Hills contain some of the world's finest caves.  Jewel Cave is currently listed as the second longest explored cave in the world while Wind Cave is the fourth longest.

The boxwork in Wind Cave represents the finest and most extensive examples of this particular type of cave feature anywhere in the world.  Jewel Cave's coatings of nail-head and dogtooth spar are world famous.

Subsequently, cavers, cave scientists, and other individuals interested in caves have extensively studied the caves of the Black Hills.  Some of that research is catalogued below.