Best spot

Seven Devils Mining District: Epidote & Red Garnet Rockhounding in Adams County, Idaho

Updated June 2026

Seven Devils is a classic Idaho skarn and copper district, where Idaho Geological Survey maps and reports emphasize limestone-garnet belts, copper deposits, and lime-silicate minerals. For collectors, that translates into a broader mineral suite than most Idaho sites: garnet, epidote, malachite, zoisite, and related contact-metamorphic material. Reported finds include epidote, red garnet, pink garnet, malachite, thulite, and more. Below: coordinates, access notes, nearby spots, and trip-planning links.

Seven Devils Mining District photos

Public image records connected to this spot or its reported material.

1 photo

Ceanothus velutinus, snowbrush ceanothus | US Forest Service Research and Development at Seven Devils Mining District, Adams County, Idaho

Quick details

Access: Public area
County: Adams County
State: Idaho
Nearest road: National Forest Development Road 493
Coordinates: 45.16617, -116.64885

Geology at Seven Devils Mining District

This spot sits on Blue Mountains island arc, quartz diorite and tonalite, mapped as hornblende quartz diorite and tonalite that formed roughly 145 to 66 million years ago. Plutonic rock like this weathers slowly into grus and boulders, and the most productive collecting is typically in weathered zones and drainages.

Mapped unit: Blue Mountains island arc, quartz diorite and tonalite
Age: 145–66 Ma (Cretaceous)
Rock types: hornblende quartz diorite and tonalite
Elevation: 6,840 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 Seven Devils Mining District

Best months: April to October. Typical highs run 75°F in midsummer and 26°F in midwinter, with winter lows near 10°F.

Climate normals: NOAA 1991-2020 monthlies, RIGGINS station (18 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

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

Found at Seven Devils Mining District

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 Seven Devils Mining District.

Across the state line from Seven Devils Mining District

Seven Devils Mining District is close enough to the Idaho border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.

Seven Devils Mining District FAQ

Where is Seven Devils Mining District?+

Seven Devils Mining District is in Adams County, Idaho, at 45.16617, -116.64885. Nearest road: National Forest Development Road 493.

What rocks and minerals can you find at Seven Devils Mining District?+

Seven Devils Mining District is reported to produce Epidote, Red Garnet, Pink Garnet, Malachite, Thulite, Zoisite.

Is collecting allowed at Seven Devils Mining District?+

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 Seven Devils Mining District?+

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 Seven Devils Mining District?+

The most comfortable months at Seven Devils Mining District are April to October.

How do I get to Seven Devils Mining District?+

Open the directions link to navigate to 45.16617, -116.64885 in Google Maps. The nearest road is National Forest Development Road 493.

More rockhounding in Idaho

See all 115 Idaho spots →

Open Seven Devils Mining District on the map

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