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Dismal Swamp: Smoky Quartz & Topaz Rockhounding in Elmore County, Idaho

Updated June 2026

Dismal Swamp is a focused Elmore County locality for smoky quartz and topaz, both listed for the area by Idaho Department of Lands and Mindat. It is a more mineral-specimen-oriented choice than many Idaho agate fields, with quartz-family collecting tied to the Rocky Bar mining district and nearby granitic terrain. Reported finds include smoky quartz, topaz. Below: coordinates, access notes, nearby spots, and trip-planning links.

Dismal Swamp photos

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

4 photos

Quick details

Access: Public area
County: Elmore County
State: Idaho
Nearest road: Trinity Ridge Road
Coordinates: 43.72904, -115.36641

Geology at Dismal Swamp

This spot sits on Biotite granodiorite, mapped as biotite granodiorite that formed roughly 145 to 66 million years ago. Granitic ground like this typically carries quartz veins and pockets, and weathered crystals tend to collect in the soils and drainages below.

Mapped unit: Biotite granodiorite
Age: 145–66 Ma (Cretaceous)
Rock types: biotite granodiorite
Elevation: 6,660 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.

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 Dismal Swamp

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 Dismal Swamp.

Dismal Swamp FAQ

Where is Dismal Swamp?+

Dismal Swamp is in Elmore County, Idaho, at 43.72904, -115.36641. Nearest road: Trinity Ridge Road.

What rocks and minerals can you find at Dismal Swamp?+

Dismal Swamp is reported to produce Smoky Quartz, Topaz.

Is collecting allowed at Dismal Swamp?+

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 Dismal Swamp?+

A rock hammer, a small pry bar, gloves, and safety glasses cover most crystal ground. A screen helps in loose pocket soil, and newspaper protects points on the way out.

How do I get to Dismal Swamp?+

Open the directions link to navigate to 43.72904, -115.36641 in Google Maps. The nearest road is Trinity Ridge Road.

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