Twin Caves

Twin Caves is a pair of cave entrances connected by a short river at the bottom of a sinkhole within the boundaries of Spring Mill State Park in Lawrence County, Indiana.

[1][2] The river is an exposed section of a mostly-underground stream that originates as Mosquito Creek several miles southeast of the park, which sinks into the Upper Twin Cave system.

The stream finally emerges at the Donaldson Cave entrance as a short tributary of Mill Creek, still within the park.

[4] The tours are operated by the Indiana Department of Natural Resources and are seasonal from Memorial Day to October.

The Shawnee (Bronson-Donaldson) Cave and Upper Twin Cave have reopened to registered groups, after a closure of several years due to white nose syndrome (WNS).