Bismark Mine: Molybdenite & Pyrite Rockhounding in Madison County, Montana

Updated June 2026

Bismark Mine is a mapped rockhounding spot in Madison County, Montana. Reported finds include molybdenite, pyrite, chalcopyrite. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Madison County
State: Montana
Nearest road: Mammoth South Boulder Road
Coordinates: 45.61285, -112.04897

Geology at Bismark Mine

This spot sits on Glacial moraine deposits, mapped as sand and gravel that formed within roughly the last 3 million years. Loose deposits like these are float-collecting ground: erosion keeps moving durable rocks and minerals into gravel bars, cutbanks, and washes.

Mapped unit: Glacial moraine deposits
Age: 3 Ma to present (Pleistocene)
Rock types: sand and gravel
Elevation: 7,400 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 Bismark Mine

Best months: April to October. Typical highs run 75°F in midsummer and 25°F in midwinter, with winter lows near 3°F. At about 7,400 ft, snow can block access from late fall well into spring, so check conditions outside of summer.

Climate normals: NOAA 1991-2020 monthlies, TWIN BRIDGES station (14 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.

State guidance last verified: April 1, 2026

BLM Montana — Recreational mineral collecting
Montana Bureau of Mines and Geology
Gem Mountain Sapphire Mine (fee-dig operator)
Community submissions reviewed against published agency rules

Found at Bismark Mine

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 Bismark Mine.

Bismark Mine FAQ

Where is Bismark Mine?+

Bismark Mine is in Madison County, Montana, at 45.61285, -112.04897. Nearest road: Mammoth South Boulder Road.

What rocks and minerals can you find at Bismark Mine?+

Bismark Mine is reported to produce Molybdenite, Pyrite, Chalcopyrite.

Is collecting allowed at Bismark Mine?+

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 Bismark Mine?+

A rock hammer, gloves, and safety glasses are enough for oxidized copper ground. Look for green and blue staining on weathered rock and in old dump piles.

When is the best time to visit Bismark Mine?+

The most comfortable months at Bismark Mine are April to October. At about 7,400 ft, snow can block access from late fall well into spring, so check conditions outside of summer.

How do I get to Bismark Mine?+

Open the directions link to navigate to 45.61285, -112.04897 in Google Maps. The nearest road is Mammoth South Boulder Road.

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Open Bismark Mine on the map

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