The federal mineral record holds 1,443 entries for Ohio — 1,287 mines that shipped ore, 12 recorded occurrences. Below it: 5 places where you can legally collect.
Mineral history, not an invitation. This mineral history comes from a federal record of historic mines, prospects, and occurrences. It is not a list of places to collect. Historic mine sites are usually on private land, under active mining claims, or unsafe to enter — and often all three. The places you can actually collect are in the legal-access directory below.
The commodities that drew miners and prospectors to Ohio, by number of historic records:
Clay · 198Limestone · 106Iron · 44Flagstone · 19Calcium · 15Silica · 11Titanium · 10Aluminum · 10
Records from the USGS Mineral Resources Data System, a legacy federal database last revised August 2022 and no longer updated.
Hours, fees, and access rules change. Verify with the operator or land agency before you go.
Caesar Creek Lake Emergency Spillway
Waynesville, OH
brachiopodstrilobiteshorn coral
Public land, rules apply · Free with permit · The spillway itself is open year-round in daylight, but the visitor center's hours gate the permit, so a holiday or off-season arrival can leave you without one. Skip the trip after heavy rain, when the spillway holds water.
Checked against its source August 16, 2026
Sylvania, OH
brachiopodshorn coraltrilobites
Public land, rules apply · Free · The digging quarry runs mid-April through October, opening 8:30 a.m. daily and closing on a sliding schedule: 6 p.m. in April, 7 p.m. in May, 7:30 p.m. in June and July, 7 p.m. in August, 6 p.m. in September, 5:30 p.m. in October. The parking lot and restrooms run year-round from 8 a.m. to 90 minutes before sunset, with holiday closures including July 1-5.
Checked against its source August 16, 2026
Hueston Woods State Park Fossil Areas
Oxford, OH
brachiopodsbryozoanshorn coral
State park dig · Free · Year-round in daylight hours. Four Mile Creek runs low and readable from late summer into fall, which is when the streambed exposures work best.
Checked against its source August 16, 2026
Fairborn, OH
silurian coralsstromatoporoidsbrachiopods
Public land, rules apply · Free · Open daily, dawn to dusk. There is almost no shade on the old quarry floor, so aim for early morning or evening in July and August. Collecting boundaries are marked on site — read the signage at the trailhead before you start.
Checked against its source August 16, 2026
Sharonville, OH
brachiopodsbryozoanshorn coral
Public land, rules apply · Free · Open daily, dawn to dusk, year-round. Portable toilets and a hand-washing station operate April through November only; picnic tables and a drinking fountain are on site.
Checked against its source August 16, 2026
Yes — at places that allow it. This page lists 5 in Ohio: fee digs, designated collecting areas, and official localities, each checked against its source. Everywhere else, legality depends on who owns the land and what rules apply. Before any trip: check land ownership and current mining claims, get permission, respect closures, and never enter old mine workings.
Treat Ohio's historic mines as history, not destinations. Most sit on private land or active mining claims, and old workings are dangerous even to walk. The mineral record on this page tells you what the ground holds — the directory tells you where you are welcome to look for it.