Fossil sites in Ohio

Caesar Creek State Park near Waynesville is the benchmark Ohio site — the Army Corps spillway below the dam is specifically managed for public fossil collection, producing trilobites, brachiopods, bryozoans, and crinoids from exposed Ordovician limestone. No permit is required; the site is open year-round.

The Cincinnatian Series of limestones and shales exposed throughout southwest Ohio represents the global reference section for Late Ordovician stratigraphy. Geologists worldwide use Cincinnati-area exposures to correlate Ordovician-age rocks because the sequence is so complete, well-studied, and accessible. Fossil Park in Sylvania is the exception in the guide — it exposes Devonian coral reef material rather than Ordovician, giving collectors a second geological era to work with.

Cross-border options: Sylvania is 90 minutes from the Detroit-Windsor crossing, and from there Rock Glen Conservation Area near Arkona, Ontario (about 2 hours further on Highway 402) exposes the same Middle Devonian Hamilton Group rocks worked at Sylvania and Penn Dixie, with a one-fossil-per-visitor souvenir-collecting policy. See the full Canadian directory at /countries/canada.