An old quarry two miles west of Rockford, Iowa, where the Lime Creek shale sheds a Devonian sea floor so thick with brachiopods that fingers are often the only tool you need. The Iowa Geological Survey puts it plainly: anyone can collect here. It is a state preserve run by the Floyd County Conservation Board, with a nature centre beside the pit, and every rain turns up a fresh crop. Nothing here ever walked on land, so come for the shells.
Brachiopods and other Devonian shells · Late Devonian, Lime Creek Formation
Open to the public for collecting, and what you find is yours to keep. Check the posted rules before you start: they can change with the season and the landowner.
Other places on the map within a couple of hours.
