Maramec Spring - 7/29/2006
Part of a Karst topographical area, with many springs and caves, it is the 5th largest spring in MO with an average discharge of 153 cubic ft/sec
Mark Twain Cave (Hannibal) - 3/27/2025
Originally McDowell's Cave, this is a show cave named for the author, playing an important role in his novel The Adventures of Tom Sawyer
Pickle Springs - 3/27/2025
This deep, forested gorge contains one of the finest Pleistocene relict habitats in Missouri, including several species characteristic of the Appalachian Mountains
