Narrow Gauge Gulch: Pyromorphite Rockhounding in Cascade County, Montana

Updated June 2026

Narrow Gauge Gulch is a mapped rockhounding spot in Cascade County, Montana. Reported finds include pyromorphite. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Cascade County
State: Montana
Nearest road: South Main Street
Postcode: 59465
Coordinates: 46.91967, -110.72410

Geology at Narrow Gauge Gulch

This spot sits on Quartzofeldspathic gneiss, mapped as gneiss that formed roughly 2500 to 1600 million years ago. Metamorphic rock like this weathers into resistant float, and minerals that survive transport typically concentrate in nearby drainages.

Mapped unit: Quartzofeldspathic gneiss
Age: 2500–1600 Ma (Paleoproterozoic)
Rock types: gneiss
Elevation: 5,800 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 Narrow Gauge Gulch

Best months: April to October. Typical highs run 79°F in midsummer and 35°F in midwinter, with winter lows near 14°F.

Climate normals: NOAA 1991-2020 monthlies, NEIHART 8 NNW station (9 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 Narrow Gauge Gulch

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

Pyromorphite

Nearby rockhounding spots

Other rockhounding spots within driving distance of Narrow Gauge Gulch.

Narrow Gauge Gulch FAQ

Where is Narrow Gauge Gulch?+

Narrow Gauge Gulch is in Cascade County, Montana, at 46.91967, -110.72410. Nearest road: South Main Street.

What rocks and minerals can you find at Narrow Gauge Gulch?+

Narrow Gauge Gulch is reported to produce Pyromorphite.

Is collecting allowed at Narrow Gauge Gulch?+

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 Narrow Gauge Gulch?+

A rock hammer, sturdy gloves, safety glasses, and a collecting bag cover the basics here. Add a spray bottle: wet rock shows color and pattern that dry rock hides.

When is the best time to visit Narrow Gauge Gulch?+

The most comfortable months at Narrow Gauge Gulch are April to October.

How do I get to Narrow Gauge Gulch?+

Open the directions link to navigate to 46.91967, -110.72410 in Google Maps. The nearest road is South Main Street.

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