Elkhorn Mountain: Magnetite & Hematite Rockhounding in Jefferson County, Montana

Quick details

Access

Public area

County

Jefferson County

State

Montana

Nearest road

Iron Mountain Road

Coordinates

46.29094, -111.93591

Geology at Elkhorn Mountain

This spot sits on Mission Canyon Formation: locally includes Big Snowy Formation in south-central Montana, mapped as limestone that formed roughly 345 to 330 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

Mission Canyon Formation: locally includes Big Snowy Formation in south-central Montana

Age

345–330 Ma (Mississippian)

Rock types

limestone

Elevation

7,480 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 Elkhorn Mountain

Best months: May to October. Typical highs run 71°F in midsummer and 25°F in midwinter, with winter lows near 0°F. At about 7,480 ft, snow can block access from late fall well into spring, so check conditions outside of summer.

Climate normals: NOAA 1991-2020 monthlies, TIZER GARDENS 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 Elkhorn Mountain

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

• MagnetiteEncyclopedia →
• HematiteEncyclopedia →