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Oakes Quarry Park: Fossil Hunting in Greene County, Ohio

Updated July 2026

Oakes Quarry Park exposes the Silurian Brassfield Formation, roughly 440 million years old, and preserves two ancient patch reefs that have yielded 29 species of crinoids, some among the largest ever described. The City of Fairborn manages the old limestone quarry specifically for public fossil collecting, an unusual designation for a municipal park. Brachiopods, bryozoans, mollusks, corals, and occasional trilobites weather out of the reef rock across the site. Reported finds include fossils, crinoids, brachiopods, corals, bryozoans. Below: coordinates, access notes, nearby spots, and trip-planning links.

Oakes Quarry Park photos

Public image records connected to this spot or its reported material.

1 photo

The exposed Silurian reef floor and a quarry pond at Oakes Quarry Park, Fairborn, Greene County, Ohio

Quick details

Access: Public area
County: Greene County
State: Ohio
Nearest road: East Xenia Drive
Postcode: 45324
Coordinates: 39.79005, -83.98205

Geology at Oakes Quarry Park

This spot sits on Cincinnati Group as used by Wickstrom (1990), mapped as shale, dolostone, and limestone that formed roughly 485 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: Cincinnati Group as used by Wickstrom (1990)
Age: 485–445 Ma (Ordovician)
Rock types: shale, dolostone, and limestone
Elevation: 900 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.

Best time to visit Oakes Quarry Park

Best months: March to November. Typical highs run 85°F in midsummer and 38°F in midwinter, with winter lows near 17°F.

Climate normals: NOAA 1991-2020 monthlies, NEW CARLISLE station (10 mi away).

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.

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.

Sources & 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.

Sources: RockHoundR public spot dataset, app land overlays, and local agency review before each trip.

Found at Oakes Quarry Park

Each chip opens all spots that produce that material; the encyclopedia link opens the full ID and field guide.

Fossils Encyclopedia →
Crinoids
Brachiopods
Corals
Bryozoans

Nearby rockhounding spots

Other rockhounding spots within driving distance of Oakes Quarry Park.

Across the state line from Oakes Quarry Park

Oakes Quarry Park 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.

Oakes Quarry Park FAQ

Where is Oakes Quarry Park?+

Oakes Quarry Park is in Greene County, Ohio, at 39.79005, -83.98205. Nearest road: East Xenia Drive.

What rocks and minerals can you find at Oakes Quarry Park?+

Oakes Quarry Park is reported to produce Fossils, Crinoids, Brachiopods, Corals, Bryozoans.

Is collecting allowed at Oakes Quarry Park?+

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. Always confirm current rules with the managing agency before a trip.

What tools should I bring to Oakes Quarry Park?+

A rock hammer, a cold chisel, safety glasses, and newspaper or foam for wrapping finds cover most fossil ground. A trowel and a sieve help in soft exposures.

When is the best time to visit Oakes Quarry Park?+

The most comfortable months at Oakes Quarry Park are March to November.

How do I get to Oakes Quarry Park?+

Open the directions link to navigate to 39.79005, -83.98205 in Google Maps. The nearest road is East Xenia Drive.

More rockhounding in Ohio

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