Cave Tour and Home Again
You’re a sixteen year old boy who has just moved to South Dakota in 1890. There’s a cave in your backyard…and your mother is still in Iowa. What would you do? Grab a candle and some string and start spelunking! Alvin McDonald spend three years exploring the cave and keeping a daily journal of his discoveries. While presenting his findings at the Columbian Exposition in Chicago, he contracted typhoid fever and died at the end of the year. He was just 20 years old.
This cave’s natural entrance is only about ten inches in diameter. Depending on the pressure difference between the outside air and the cave air, it is either “breathing” in or out from this orifice. This Spirit Wind figures prominently in the creation story of the Lakota people.
How were you breathed into being?
This cave differs from the others I’ve visited (Mammoth Cave, KY; Carlsbad Caverns, NM; Cave of the Mounds, WI) in that its formations are mostly boxwork, rather than stalactites and stalagmites. Boxwork is kind of like what you’d see if you built a castle of sugar cubes and mortared it with cement. The sugar cubes dissolve, and what is left is a kind of honeycomb of borders, criss-crossing each other. The calcite “mortar” that filled cracks in the limestone and dolomite is what remains. These structures were formed at the genesis of the cave, and not later by the action of dripping moisture, so they are speleogens rather than speleothems. (My new word for this section of the trip!) The ranger asked us what we thought it looked like. My first response was “a Jackson Pollack painting”. 
