Iron Mountain: Yellow Garnet & Apatite Rockhounding in Saint Francois County, Missouri

Updated June 2026

Iron Mountain is a mapped rockhounding spot in Saint Francois County, Missouri. Reported finds include yellow garnet, apatite, barite, calcite, diopside, and more. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Saint Francois County
State: Missouri
Postcode: 63656
Coordinates: 37.70924, -90.63430

Geology at Iron Mountain

This spot sits on St. Francois mountains volcanic supergroup, mapped as rhyolite that formed roughly 1600 to 1000 million years ago. Volcanic ground like this weathers into rocky slopes and float, and fresh exposures in cuts and drainages are usually the most productive places to look.

Mapped unit: St. Francois mountains volcanic supergroup
Age: 1600–1000 Ma (Mesoproterozoic)
Rock types: rhyolite
Elevation: 1,330 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 Iron Mountain

Best months: February to December. Typical highs run 87°F in midsummer and 41°F in midwinter, with winter lows near 21°F.

Climate normals: NOAA 1991-2020 monthlies, FARMINGTON station (14 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.

Sources: RockHoundR public spot dataset, app land overlays, and local agency review before each trip.

Found at Iron Mountain

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 Iron Mountain.

Across the state line from Iron Mountain

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

Iron Mountain FAQ

Where is Iron Mountain?+

Iron Mountain is in Saint Francois County, Missouri, at 37.70924, -90.63430.

What rocks and minerals can you find at Iron Mountain?+

Iron Mountain is reported to produce Yellow Garnet, Apatite, Barite, Calcite, Diopside, Dolomite, Epidote, Fluorite, Galena, Magnetite, Quartz.

Is collecting allowed at Iron Mountain?+

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 Iron Mountain?+

A rock hammer, gloves, and safety glasses cover old mining-district ground. Stay out of shafts and adits; the best specimens typically come from dump piles.

When is the best time to visit Iron Mountain?+

The most comfortable months at Iron Mountain are February to December.

How do I get to Iron Mountain?+

Open the directions link to navigate to 37.70924, -90.63430 in Google Maps. Some spots are remote, so check road conditions before driving out.

More rockhounding in Missouri

See all 94 Missouri spots →

Open Iron Mountain on the map

Use the RockHoundR app for live land overlays, weather, geology, directions, and saved finds.