The city of Sylvania, Ohio has a quarry that dumps fresh Silica Shale into a public pit twice a year. The shale splits easily and the fossils inside are famously well preserved: complete trilobites, brachiopods, horn corals, crinoids. Free, no permit, bring a bucket and safety glasses. Restocked, so it does not get picked out.
Trilobites, brachiopods, corals · Devonian, ~375 mya
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Other places on the map within a couple of hours.