Bronk Quarry: Calcite & Dolomite Rockhounding in Winona County, Minnesota

Updated June 2026

Bronk Quarry is a mapped rockhounding spot in Winona County, Minnesota. Reported finds include calcite, dolomite, goethite, hematite, marcasite, and more. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Winona County
State: Minnesota
Nearest road: Seminary Drive
Postcode: 55988
Coordinates: 44.03381, -91.72269

Geology at Bronk Quarry

This spot sits on Oneota Dolomite, mapped as dolostone that formed roughly 485 to 470 million years ago. Carbonate rock like this is the classic host for lead, zinc, and fluorite mineralization, which typically follows old cavities and replacement zones.

Mapped unit: Oneota Dolomite
Age: 485–470 Ma (Early Ordovician)
Rock types: dolostone
Elevation: 1,100 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 Bronk Quarry

Best months: April to October. Typical highs run 83°F in midsummer and 26°F in midwinter, with winter lows near 9°F.

Climate normals: NOAA 1991-2020 monthlies, WINONA station (4 mi away), adjusted for elevation.

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 Bronk 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 Bronk Quarry.

Across the state line from Bronk Quarry

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

Bronk Quarry FAQ

Where is Bronk Quarry?+

Bronk Quarry is in Winona County, Minnesota, at 44.03381, -91.72269. Nearest road: Seminary Drive.

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

Bronk Quarry is reported to produce Calcite, Dolomite, Goethite, Hematite, Marcasite, Pyrite.

Is collecting allowed at Bronk 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.

What tools should I bring to Bronk Quarry?+

A rock hammer, gloves, and safety glasses cover old mining-district ground. Stay out of shafts and adits; the best specimens typically come from dump piles.

When is the best time to visit Bronk Quarry?+

The most comfortable months at Bronk Quarry are April to October.

How do I get to Bronk Quarry?+

Open the directions link to navigate to 44.03381, -91.72269 in Google Maps. The nearest road is Seminary Drive.

More rockhounding in Minnesota

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Open Bronk Quarry on the map

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