We learned that there are several caves and caverns in the Black Hills.  We visited two of them, the first is Wind Cave (look for a post with pictures of the second one shortly).  It’s the first cave that became a National Park, back in 1905 and contains a huge area of land around the cave itself so that the forests and hills are protected.

There is a herd of bison in the national park, as well as lots of deer, antelope, and long-horn sheep.  We didn’t see many animals while driving to the cave though 🙁

But, the cave itself is interesting.  As with most of the caves in this area, there are very few stalagmites and stalactites due to a low amount of water seeping into the caves.  There are, however, formations called boxworks which were formed when carbolic acid (the mixture of water and CO2) seeped through the ground containing a mixture of fossilized sea creatures and gypsum, dissolving the fossils but was not acidy enough to dissolve the gypsum, so you’re left with lacy, spiderwebby looking formations.  Here is one picture of the boxworks:

And, here are more pictures of the cave: