Twin caves

Twin Caves is part of the Donaldson/Bronson/Twin system located in Lawrence County, Indiana, within the boundaries of Spring Mill State Park. The system stretches more than four miles.

The Twin Caves sections hold most of the system (3.6 miles of it), and boat tours are offered into Northern Twin cave located in Spring Mill State Park. The tours last 20 minutes and go about 600 ft back and turn around.

The tours are operated by the Indiana Department of Natural Resources and are seasonal from Memorial Day - October.

Donaldson Cave is also open to the public but there is no lighting and no guided tours. The part open to the public, called the "Dry side of Donaldson", does not require permits, and goes back about 100 ft with a 600 ft long side passage.

The "Wet side of Donaldson", also called the Spring Exit or Shawnee cave, requires a permit and certain requirements to enter. It is possible to do a 6,500 ft through trip from the Donaldson Exit to the Bronson Entrance/Exit, both located in Spring Mill State Park.