The Trammel family gave this hillside in Sharonville, outside Cincinnati, to the city so people could come and do exactly this. Four of the classic Cincinnatian layers are exposed on the slope, and the old sea floor weathers out of them after every rain. Entry is free and the city says you may keep what you find. Take a representative handful, leave the rest for the next family, and pick from the surface: digging into the hillside is not allowed.
Brachiopods, bryozoans, crinoid stems · Late Ordovician, ~450 mya
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.
