Defiance Quarry — Rockhounding in Saint Charles County, Missouri

Defiance Quarry is a mapped rockhounding spot in Saint Charles County, Missouri. Reported finds include yellow calcite, white calcite, goethite, marcasite, pyrite, and more. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Saint Charles County
State: Missouri
Nearest road: MO DD
Postcode: 63341
Coordinates: 38.66076, -90.77598

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 Defiance Quarry

Each chip 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 Defiance Quarry.

Across the state line from Defiance Quarry

Defiance Quarry is close enough to the Missouri border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.

Defiance Quarry FAQ

Where is Defiance Quarry?+

Defiance Quarry is in Saint Charles County, Missouri, at 38.66076, -90.77598. Nearest road: MO DD.

What rocks and minerals can you find at Defiance Quarry?+

Defiance Quarry is reported to produce Yellow Calcite, White Calcite, Goethite, Marcasite, Pyrite, Sphalerite, Fossils.

Is collecting allowed at Defiance Quarry?+

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.

How do I get to Defiance Quarry?+

Open the directions link to navigate to 38.66076, -90.77598 in Google Maps. The nearest road is MO DD.

More rockhounding in Missouri

See all 94 Missouri spots →

Open Defiance Quarry on the map

Use the RockHoundR app for live land overlays, weather, geology, directions, and saved finds.