Wind Cave National Park in South Dakota was established January 9, 1903.  The park isn’t huge, only 28,000 acres and most people  that come here spend their time underground, even though there is plenty of wildlife to see roaming the grasslands.There are 53 miles of explored passages in Wind Cave, making it the third longest cave in the United States and the seventh longest in the world.  The cave is a ‘dry’ cave, meaning there is no moisture creeping through the limestone rocks that create stalagtites and stalagmites.  It does, however, have many unusual mineral formations, including the world’s best collection of boxwork; a calcite formation resembling irregular honeycombs. A distinctive feature of Wind Cave is a strong wind that rushes in and out of the mouth of the cave equalizing air pressure between the inside passageways and the atmosphere outside.  Because it is a cave system the park is open all year round and the temperature underground stays ‘relatively’ constant.

Most caves are thought to have little to no change in temperature but the noticeable wind movement at the entrance to this cave system prompted a study in 1984-85.  A concluding summary was:  “The real weather (i.e. daily changes in the cave’s atmospheric conditions) of Wind Cave is driven by the wind. Few caves experience the volume of airflow which Wind Cave exhibits. On average, almost 1,000,000 cubic feet of air enter or leave the cave per hour when the Walk-In Entrance is open! That’s enough air to completely fill a cave 10 feet wide, 10 feet tall, and almost 2 miles long! Since it takes a long time for a volume of air this large to warm or cool to cave temperature, temperature changes can occur surprisingly deep into the cave on days when the cave is inhaling. The Wind Cave Climate Study of 1984-85 showed that with the Walk-In Entrance open in the winter, temperatures could fluctuate by over 12°F as far into the cave as the Post Office (over 500 feet from the entrance). The entire Half-Mile Tour route is almost always cooler than the 55°F deep cave temperature, mostly due to cold air brought into the cave during the winter. So much for constant temperatures at Wind Cave!”

Tours are led by Park Rangers and if you are claustrophobic you had best stay topside.  Many of the passages are narrow and you need to duck or dodge to avoid formations.  Even the shorter tours include as many as 450 steps up and down.  You descend 200′ below the surface on the tour we took.

I love caves and Wind Cave was quite different from many others we have toured.
                 Wind Cave’s famous calcite boxwork formations.
  Since I like take photographs I lingered at the back of the group to avoid too many bodies in my shots.  This however, did create lots of pictures of John’s back in his Disney “Grumpy” hoodie.