Lost River, Indiana: The River That Disappears Underground

In the farm country of southern Indiana, there's a river that keeps disappearing. The Lost River starts out like any other stream in Washington County and runs about 87 miles before joining the East Fork of the White River. But for at least 23 miles of its main course, it doesn't run on the surface at all. It sinks into the ground and flows through underground channels in the limestone, which is how it got its name. Those channels have never been fully explored, and they may stretch for hundreds of miles. This happens because the land here is karst: limestone bedrock that rainwater slowly dissolves, carving out cracks, caves and sinkholes. On the Mitchell Plain of Orange County, the ground is riddled with them. When the Lost River reaches this area, its water drains down into the rock and keeps flowing underground, while the riverbed above often sits dry. In a few places, the underground river shows itself. The most dramatic is Wesley Chapel Gulf, near Orleans. Long ago, the rock roof over one of the river's underground channels collapsed, leaving a sunken box canyon about 8.3 acres in size, with bedrock walls 30 to 100 feet high. Inside it, the Lost River briefly comes to the surface, then disappears into the ground again. It's probably the largest sinkhole in Indiana, and in 1972 it was designated a National Natural Landmark. The U.S. Forest Service acquired the land in 1996, and it's now part of the Hoosier National Forest. A few miles west, in the town of Orangeville, water wells up from a cave into a rock-walled pool about 220 feet across. This is the Orangeville Rise, the second-largest spring in Indiana, and it was also named a National Natural Landmark in 1972. For a long time, people believed this was where the Lost River came back up. It isn't. The Orangeville Rise drains a separate area of sinkholes and is a tributary. The main river resurfaces about 2 miles south of Orangeville, at a spring known as the True Rise. The Indiana Karst Conservancy has cared for the Orangeville Rise since 1999. Above ground, most of the region looks like ordinary Indiana fields and forest, while the river runs beneath it.