Another Minnesota "Mystery": The Karst of Southeastern MN

On the surface of things, Minnesota is a beautiful state.  We know that.  Descend underground, though, and Minnesota still cannot fail to impress.  There's the mystery of Devil's Kettle and the disappearing waterfall.  There's the Soudan Mine and the high-energy physics lab it houses.  And there's the entire southeastern corner of the state, home to karst topography and most notably Mystery Cave.

Karst topography occurs in areas of water-soluble rock such as limestone or dolomite, and is characterized by features such as caves, sinkholes, springs, and rivers that drop underground.  The southeastern corner of Minnesota has plenty of sinkholes and even claims to be the sinkhole capital of the United States.

Mystery Cave is the longest cave system in the Upper Midwest, stretching at least 13 miles (plus some possibly undiscovered passages).  It was found by farmer Joseph Petty in the late 1930s when he noticed suspiciously snowless areas during a Minnesota winter (the cave remains 48 degrees year-round, and it had melted the snow on the ground above it).

Mystery Cave and nearby Niagara Cave are popular sightseeing destinations.  The underground worlds display natural artworks beyond traditional stalactites (c for ceiling, t for top) and stalagmites (g for ground).  Some favorite features of Mystery Cave are ribbons of rock called cave bacon, rivulets of color caused by minerals carried on the water, large and small fossils, and Turquoise Lake.  Niagara Cave boasts charismatically-named features like Paul Bunyan's Bed, Elephant's Head, an echo chamber, and, of course, a 60-foot waterfall.  There are tours for all levels of adventure.

The caves of southeastern Minnesota may be invisible when you return to the surface, but the karst geography has a big effect on the environment.  Chilled water that has flowed through the caves provides the ideal habitat for trout.  Unstable ground doesn't hold standing water well, so there are few mosquitoes.  The area is also "driftless," meaning it wasn't squashed by the last round of glaciers, but runoff from the huge chunks of ice formed deep, cutting rivers that resulted in steep valleys and bluffs.  This results in a varied landscape that can provide home to an abundance of animals, compounded by its location between two biomes: tallgrass prairie and deciduous forest.

The long and the short of it is, southeastern Minnesota is a great spot for an August campout: plenty of wildlife, few mosquitoes, cool caves to beat the heat, and geologic sights to see.  And that's not even taking into consideration historic Forestville.

References and Photo Credits

Midwest Weekends (2015). "Minnesota's Cave Country."  Accessed 8/14/15.  http://midwestweekends.com/plan_a_trip/nature/parks_natural_areas/minnesota_caves.html

Minnesota Department of Natural Resources. "Forestville/Mystery Cave State Park - Park Info."  Accessed 8/14/15.  http://dnr.state.mn.us/state_parks/forestville_mystery_cave/narrative.html

Uniquely Minnesota. "Mystery Cave & Niagara Cave Tours: Minnesota from the Inside."  Accessed 8/14/15.  http://www.uniquelyminnesota.com/features/mystery-cave-niagara-cave-tours-mn.htm

Photo Credits

All photos sourced from Wikimedia Commons.  Credit to McGhiever, DanielCD, and Tisius Syracuse.