Donaldson Cave (Shawnee Cave) – Spring Mill State Park – Indiana
The cave is part of a system of tunnels that extend more than 8000 feet within Spring Mill State Park. Other caves in the system include Bronson Cave and Twin Caves. The latter is large enough to accommodate a boat operated by park personnel, that explores the parks underlying karst (limestone) landscape.
Southern Indiana, and Kentucky are well known for their karst-related features. Signs for a variety of cave tours can be seen along the major highway systems. These include Marengo Cave, Squire Boone Caverns, Bluespring Caverns, and of course the world famous Mammoth Cave National Park outside of Brownsville, KY.
Indiana Geological & Water Survey – Karst Features in Indiana
Indiana Department of Natural Resources – Spring Mill State Park
National Park Service – Mammoth Cave National Park