At Wind Cave National Park, we descended 175 feet into a cave believed by local Native Americans to be an entrance to the spirit world, and the birthplace of the buffalo.  The rock in this cave dates back 320 million years.  Sixty million years ago, the forces that uplifted the Rocky Mountains also raised the modern Black Hills, and this multi-layered cave was born.  Intervening cracks, stresses, water erosion, and tectonic shifts created a three-dimensional network of passages, as well as exposed thin, honeycomb-shaped structures (called boxwork) which protrude from the walls and ceilings.  Wind cave is one of the few places in the world where boxwork is found.

 

 

 



 

The following is a photo of a fault line seen from within the earth.  The right side of the fault line has slipped six inches below the left.  Beware!