Basin: Gold Prospecting in Jefferson County, Montana

Updated June 2026

Basin is a mapped rockhounding spot in Jefferson County, Montana. Reported finds include silver, gold. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Jefferson County
State: Montana
Postcode: 59631
Coordinates: 46.29605, -112.23273

Geology at Basin

This spot sits on Biotite-hornblende granodioritic rocks along the Continental Divide, Anaconda Range, Sapphire Mountains, and Flint Creek Range, mapped as biotite-hornblende granodiorite, biotite-hornblende monzogranite, and tonalite that formed roughly 145 to 66 million years ago. Gold in granitic terrain like this is typically tied to quartz veins along contacts and shear zones, with placer color in the streams that drain them.

Mapped unit: Biotite-hornblende granodioritic rocks along the Continental Divide, Anaconda Range, Sapphire Mountains, and Flint Creek Range
Age: 145–66 Ma (Cretaceous)
Rock types: biotite-hornblende granodiorite, biotite-hornblende monzogranite, and tonalite
Elevation: 6,020 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 Basin

Best months: April to October. Typical highs run 79°F in midsummer and 31°F in midwinter, with winter lows near 8°F.

Climate normals: NOAA 1991-2020 monthlies, BOULDER station (7 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 Basin

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 Basin.

Basin FAQ

Where is Basin?+

Basin is in Jefferson County, Montana, at 46.29605, -112.23273.

What rocks and minerals can you find at Basin?+

Basin is reported to produce Silver, Gold.

Is collecting allowed at Basin?+

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 Basin?+

A gold pan, a classifier screen, a small shovel, and a snuffer bottle cover the basics. Motorized equipment and sluices fall under separate rules in most states, so start with hand tools.

When is the best time to visit Basin?+

The most comfortable months at Basin are April to October.

How do I get to Basin?+

Open the directions link to navigate to 46.29605, -112.23273 in Google Maps. Some spots are remote, so check road conditions before driving out.

More rockhounding in Montana

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Open Basin on the map

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