Phillipsburg: Chrysocolla & Rhodochrosite Rockhounding in Granite County, Montana

Updated June 2026

Phillipsburg is a mapped rockhounding spot in Granite County, Montana. Reported finds include chrysocolla, rhodochrosite, ore. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Granite County
State: Montana
Nearest road: Granite Rd
Postcode: 59858
Coordinates: 46.31933, -113.28055

Geology at Phillipsburg

This spot sits on Red Lion Formation, Hasmark Formation, Silver Hill Formation, and Flathead Sandstone, undivided, mapped as limestone, shale, dolomite, and quartzite that formed roughly 540 to 485 million years ago. Carbonate rock like this dissolves and weathers readily, so fresh road cuts, quarries, and creek exposures are typically the most productive ground.

Mapped unit: Red Lion Formation, Hasmark Formation, Silver Hill Formation, and Flathead Sandstone, undivided
Age: 540–485 Ma (Cambrian)
Rock types: limestone, shale, dolomite, and quartzite
Elevation: 5,730 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 Phillipsburg

Best months: March to October. Typical highs run 79°F in midsummer and 34°F in midwinter, with winter lows near 14°F.

Climate normals: NOAA 1991-2020 monthlies, PHILIPSBURG RS station (1 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 Phillipsburg

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 Phillipsburg.

Phillipsburg FAQ

Where is Phillipsburg?+

Phillipsburg is in Granite County, Montana, at 46.31933, -113.28055. Nearest road: Granite Rd.

What rocks and minerals can you find at Phillipsburg?+

Phillipsburg is reported to produce Chrysocolla, Rhodochrosite, Ore.

Is collecting allowed at Phillipsburg?+

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 Phillipsburg?+

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 Phillipsburg?+

The most comfortable months at Phillipsburg are March to October.

How do I get to Phillipsburg?+

Open the directions link to navigate to 46.31933, -113.28055 in Google Maps. The nearest road is Granite Rd.

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