Grouse Creek: Banded Agate & Iris Agate Rockhounding in Washington County, Idaho

Updated June 2026

Grouse Creek is a mapped rockhounding spot in Washington County, Idaho. Reported finds include banded agate, iris agate, chalcedony. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Washington County
State: Idaho
Coordinates: 44.37584, -117.17385

Geology at Grouse Creek

This spot sits on Columbia River Basalt Group, mapped as basalt and basaltic andesite that formed roughly 20 to 5 million years ago. Volcanic ground like this is where agate, jasper, and other chalcedony typically form, filling old gas pockets and fracture seams in the flow rock.

Mapped unit: Columbia River Basalt Group
Age: 20–5 Ma (Early Miocene to Late Miocene)
Rock types: basalt and basaltic andesite
Elevation: 3,410 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 Grouse Creek

Best months: March to October. Typical highs run 89°F in midsummer and 32°F in midwinter, with winter lows near 16°F.

Climate normals: NOAA 1991-2020 monthlies, HUNTINGTON station (4 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 Grouse Creek

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 Grouse Creek.

Across the state line from Grouse Creek

Grouse Creek 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.

Grouse Creek FAQ

Where is Grouse Creek?+

Grouse Creek is in Washington County, Idaho, at 44.37584, -117.17385.

What rocks and minerals can you find at Grouse Creek?+

Grouse Creek is reported to produce Banded Agate, Iris Agate, Chalcedony.

Is collecting allowed at Grouse Creek?+

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 Grouse Creek?+

Most agate and jasper is surface float: bring a spray bottle, a pick or small shovel, and a sturdy bag. Wet stones show their banding and translucence.

When is the best time to visit Grouse Creek?+

The most comfortable months at Grouse Creek are March to October.

How do I get to Grouse Creek?+

Open the directions link to navigate to 44.37584, -117.17385 in Google Maps. Some spots are remote, so check road conditions before driving out.

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Open Grouse Creek on the map

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