Lost River (Indiana)

The river's underground channels may in fact cover hundreds of miles, as the caverns have never been fully explored.

The river disappears into a series of sink holes of the type that are abundant in the karstland of southern Indiana.

Where the river rises to the surface in Orange County it produces a spring that is 165 feet (50 m) deep, with the very bottom connecting to the actual underground channel.

[7] A USGS stream gauge on the river near Prospect recorded a mean annual discharge of 282.3 cu ft/s (7.99 m3/s) during water years 2010–2019.

[8] The submerged river and its tributaries probably flow through not one, but a multitude of different channels in the Orleans-Paoli area, most of which are unmapped or poorly understood.

Since 1996 a group from primarily the St. Joseph Valley Grotto has been surveying passages of what is now called the Lost River System.

The Wesley Chapel Gulf in eastern Orangeville Township is a 8.3 acres (34,000 m2) sinkhole which was caused by the collapse of the rock roof over one of the underground channels of the Lost River.