Caesar Creek Lake Spillway: Fossil Hunting in Warren County, Ohio
- Minerals reported
- 5
- Elevation
- 910 ft
The emergency spillway below Caesar Creek dam cut through Upper Ordovician bedrock and exposed one of the richest fossil beds in the eastern United States, packed with brachiopods, bryozoans, crinoids, horn corals, and the trilobite Isotelus, the animal Ohio adopted as its state invertebrate fossil. The U.S. Army Corps of Engineers opens the spillway to the public and lets visitors keep loose surface fossils, a rare exception on Corps land. Winter freeze and thaw constantly break up the shale, so the exposure re-seeds itself with fresh material every spring. Reported finds include fossil, trilobite, brachiopod, crinoid, bryozoan. Below: coordinates, access notes, nearby spots, and trip-planning links.
Plan your visit
Generally open to casual rockhounding
- County
- Warren County
- State
- Ohio
- Nearest road
- North Clarksville Road
- Postcode
- 45068
- Coordinates
- 39.48778, -84.06403
Coordinates are approximate. Confirm the exact ground in the RockHoundR app, where land overlays show which agency manages the area.
Land & collecting status
Generally open to casual rockhounding
Most public-tagged spots sit on BLM, U.S. Forest Service, or other federal land where reasonable hand collecting of common rocks and minerals is allowed. Confirm posted rules and active mining claims before you dig.
Access note: Free to collect, but a free permit is required and is issued on the spot at the Caesar Creek Lake Visitor Center (4020 North Clarksville Road, Waynesville). Rules: surface collecting only, no tools or digging, do not climb the spillway walls, and keep nothing larger than the palm of your hand. Collecting is limited to the spillway itself, not the surrounding park.
Public-land rules vary by agency, season, and field office. The RockHoundR app pulls live BLM, USFS, NPS, and tribal overlays so you can see exactly which agency manages the ground at this spot.
Geology at Caesar Creek Lake Spillway
This spot sits on Drakes, Whitewater and Liberty Formations, Undivided, mapped as shale and limestone that formed roughly 455 to 445 million years ago. Limestone like this typically forms in ancient seas, so marine fossils such as brachiopods, corals, and crinoids tend to weather out of fresh exposures.
- Mapped unit
- Drakes, Whitewater and Liberty Formations, Undivided
- Age
- 455–445 Ma (Late Ordovician)
- Rock types
- shale and limestone
- Elevation
- 910 ft
Geologic mapping via Macrostrat and the underlying state geological survey maps (CC BY 4.0). Bedrock at the surface can vary within a mapped unit.
Today's weather
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Get the appSources & verification
Spot details combine the public RockHoundR location dataset, normalized mineral labels, agency land-status checks in the app, and community submissions. Coordinates are approximate until verified in the field.
- Ohio Geological Survey
- Ohio State Parks rules
- Wayne National Forest
- Community submissions reviewed against published agency rules
Found at Caesar Creek Lake Spillway
Each name opens all spots that produce that material; the encyclopedia link opens the full ID and field guide.
Nearby rockhounding spots
Other rockhounding spots within driving distance of Caesar Creek Lake Spillway.
- Oakes Quarry ParkGreene County, Ohio · 21 mi awayFossil, Crinoid, Brachiopod
- Trammel Fossil ParkHamilton County, Ohio · 23 mi awayFossil, Trilobite, Brachiopod
- MilfordHamilton County, Ohio · 24 mi awayDiamond
- Hueston Woods State ParkPreble County, Ohio · 37 mi awayFossil, Trilobite, Brachiopod
- Sinking SpringHighland County, Ohio · 46 mi awayHematite
- ChillicotheRoss County, Ohio · 52 mi awayPyrite
- ColumbusFranklin County, Ohio · 63 mi awayPyrite
- Delaware CountyDelaware County, Ohio · 74 mi awayPyrite
Across the state line from Caesar Creek Lake Spillway
Caesar Creek Lake Spillway is close enough to the Ohio border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.
- WeisburgDearborn County, Indiana · 56 mi awayTrilobite
- New PointDecatur County, Indiana · 69 mi awayChalcopyrite
Caesar Creek Lake Spillway FAQ
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