Wyandotte Caves

Wyandotte Caves is a plural for a reason. There are two: Wyandotte Cave, usually called the Historic Cave, and Little Wyandotte, also known as Siberts Cave or the New Cave. They sit close together above the Ohio River in Crawford County, Indiana, five miles northeast of Leavenworth, are owned and run by the same people, and are otherwise very different animals. The Historic Cave is the big one, part of the fifth largest cave system in Indiana. Little Wyandotte is a short, heavily decorated walk.

The limestone they formed in was laid down in the Mississippian, between about 360 and 325 million years ago, when a shallow inland sea covered Indiana. The caves themselves began opening out in the Pliocene, roughly two million years ago, as water dissolved passage through that rock.

The ice sheets never quite reached Crawford County, but they shaped these caves all the same. Meltwater and the reorganisation of drainage that came with the forming of the Ohio River changed how water moved through the limestone, and the caves grew accordingly. Wyandotte was designated a National Natural Landmark in 1972.

The human history runs deep. Native people mined this cave for chert and for aragonite long before Europeans arrived, and saltpetre was worked here for gunpowder. The Historic Cave holds Monument Mountain, a huge breakdown mound rising inside a chamber, which was for a long time promoted as one of the largest underground mountains in the world.

The caves are now part of O'Bannon Woods State Park within Harrison-Crawford State Forest. Access has been intermittent in recent years because of white nose syndrome in the bat population, so check the park's current status with Indiana DNR before driving out.