Platteville: Barite & Calcite Rockhounding in Grant County, Wisconsin

Plan your visit

Generally open to casual rockhounding

County

Grant County

State

Wisconsin

Nearest road

West Main Street

Postcode

53818

Coordinates

42.73456, -90.48031

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.

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.

Best time to visit Platteville

Comfortable months (45 to 90°F highs)

Best months: April to November. Typical highs run 82°F in midsummer and 26°F in midwinter, with winter lows near 10°F.

Climate normals: NOAA 1991-2020 monthlies, PLATTEVILLE station (1 mi away).

Geology at Platteville

This spot sits on Sinnipee Group, mapped as dolostone that formed roughly 485 to 445 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

Sinnipee Group

Age

485–445 Ma (Ordovician)

Rock types

dolostone

Elevation

1,000 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.

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.

• Wisconsin Geological and Natural History Survey
• Wisconsin DNR property rules
• Chequamegon-Nicolet National Forest
• Community submissions reviewed against published agency rules