Pipe Creek Sinkhole near Swayzee in Grant County, Indiana, is one of the most important paleontological sites in the interior of the eastern half of North America, preserved because it was buried by glacial till. Uncovered in 1996 by workers at the Pipe Creek Junior limestone quarry, the sinkhole has yielded a diverse array of fossils from the Pliocene epoch dating back five million years. Discoveries have been made there of the remains of camelids, bears, beavers, frogs, snakes, turtles and several previously unknown species of rodents. Two fish taxa, bullhead (Ameiurus) and sunfish (Centrarchidae), have also been found there.