Gem Mountain Sapphire Mine: Sapphire Rockhounding in Granite County, Montana

Updated June 2026

Gem Mountain Sapphire Mine is a mapped rockhounding spot in Granite County, Montana. Reported finds include sapphire. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Granite County
State: Montana
Coordinates: 46.24675, -113.59216

Geology at Gem Mountain Sapphire Mine

This spot sits on Surficial 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: Surficial deposits
Age: 3 Ma to present (Pleistocene to Holocene)
Rock types: sand and gravel
Elevation: 5,560 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 Gem Mountain Sapphire Mine

Best months: March to October. Typical highs run 80°F in midsummer and 35°F in midwinter, with winter lows near 14°F.

Climate normals: NOAA 1991-2020 monthlies, PHILIPSBURG RS station (15 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 Gem Mountain Sapphire Mine

Each chip opens all spots that produce that material; the encyclopedia link opens the full ID and field guide.

Sapphire Encyclopedia →

Nearby rockhounding spots

Other rockhounding spots within driving distance of Gem Mountain Sapphire Mine.

Across the state line from Gem Mountain Sapphire Mine

Gem Mountain Sapphire Mine is close enough to the Montana border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.

Gem Mountain Sapphire Mine FAQ

Where is Gem Mountain Sapphire Mine?+

Gem Mountain Sapphire Mine is in Granite County, Montana, at 46.24675, -113.59216.

What rocks and minerals can you find at Gem Mountain Sapphire Mine?+

Gem Mountain Sapphire Mine is reported to produce Sapphire.

Is collecting allowed at Gem Mountain Sapphire 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 Gem Mountain Sapphire Mine?+

A rock hammer, a sieve, and a small shovel work well for garnet-type minerals, which concentrate as resistant grains in soils and creek gravels.

When is the best time to visit Gem Mountain Sapphire Mine?+

The most comfortable months at Gem Mountain Sapphire Mine are March to October.

How do I get to Gem Mountain Sapphire Mine?+

Open the directions link to navigate to 46.24675, -113.59216 in Google Maps. Some spots are remote, so check road conditions before driving out.

More rockhounding in Montana

See all 106 Montana spots →

Open Gem Mountain Sapphire Mine on the map

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