Ima Mine: Tungsten & Tetrahedrite Rockhounding in Lemhi County, Idaho

Plan your visit

Confirm rules before collecting

County

Lemhi County

State

Idaho

Nearest road

Patterson Creek Road

Postcode

83253

Coordinates

44.53364, -113.69225

Coordinates are approximate. Confirm the exact ground in the RockHoundR app, where land overlays show which agency manages the area.

Land & collecting status

Confirm rules before collecting

Land status here is not confirmed. Verify with the managing agency before collecting, federal, state, and tribal rules differ.

Access note: BLM records active mining claims in this area. Collecting from inside an active claim needs the claim holder's permission.

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.

Best time to visit Ima Mine

Comfortable months (45 to 90°F highs)

Best months: March to October. Typical highs run 81°F in midsummer and 26°F in midwinter, with winter lows near 0°F.

Climate normals: NOAA 1991-2020 monthlies, MAY 2SSE station (10 mi away), adjusted for elevation.

Geology at Ima Mine

This spot sits on Lawson Creek Formation, Swauger Formation, Gunsight Formation, Apple Creek Formation, Big Creek Formation, West Fork Formation, Inyo Creek Formation, Hoodoo Quartzite, and Yellowjacket Formation, undivided, mapped as phyllitic quartzite, slate, siltstone, arkose, and sandstone that formed roughly 1600 to 1000 million years ago. Metamorphic rock like this weathers into resistant float, and minerals that survive transport typically concentrate in nearby drainages.

Mapped unit

Lawson Creek Formation, Swauger Formation, Gunsight Formation, Apple Creek Formation, Big Creek Formation, West Fork Formation, Inyo Creek Formation, Hoodoo Quartzite, and Yellowjacket Formation, undivided

Age

1600–1000 Ma (Mesoproterozoic)

Rock types

phyllitic quartzite, slate, siltstone, arkose, and sandstone

Elevation

6,670 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.

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

• Idaho Panhandle National Forests, Emerald Creek
• Idaho Geological Survey
• Spencer Opal Mines (fee-dig operator)
• Community submissions reviewed against published agency rules