Crystal Butte: Andesine Rockhounding in Fremont County, Idaho

Updated June 2026

Crystal Butte is a mapped rockhounding spot in Fremont County, Idaho. Reported finds include andesine. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Fremont County
State: Idaho
Coordinates: 44.29176, -111.70045

Geology at Crystal Butte

This spot sits on Basalt (Pleistocene and Pliocene), mapped as basalt that formed within roughly the last 4 million years. 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: Basalt (Pleistocene and Pliocene)
Age: 4 Ma to present (Late Pliocene to Late Pleistocene)
Rock types: basalt
Elevation: 6,960 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 Crystal Butte

Best months: April to October. Typical highs run 75°F in midsummer and 24°F in midwinter, with winter lows near 4°F.

Climate normals: NOAA 1991-2020 monthlies, ISLAND PARK station (19 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 Crystal Butte

Each chip opens all spots that produce that material; the encyclopedia link opens the full ID and field guide.

Andesine

Nearby rockhounding spots

Other rockhounding spots within driving distance of Crystal Butte.

Across the state line from Crystal Butte

Crystal Butte 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.

Crystal Butte FAQ

Where is Crystal Butte?+

Crystal Butte is in Fremont County, Idaho, at 44.29176, -111.70045.

What rocks and minerals can you find at Crystal Butte?+

Crystal Butte is reported to produce Andesine.

Is collecting allowed at Crystal Butte?+

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 Crystal Butte?+

A rock hammer, sturdy gloves, safety glasses, and a collecting bag cover the basics here. Add a spray bottle: wet rock shows color and pattern that dry rock hides.

When is the best time to visit Crystal Butte?+

The most comfortable months at Crystal Butte are April to October.

How do I get to Crystal Butte?+

Open the directions link to navigate to 44.29176, -111.70045 in Google Maps. Some spots are remote, so check road conditions before driving out.

More rockhounding in Idaho

See all 115 Idaho spots →

Open Crystal Butte on the map

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