Fandango Pass: Agate & Chalcedony Rockhounding in Modoc County, California

Updated June 2026

Fandango Pass is a mapped rockhounding spot in Modoc County, California. Reported finds include agate, chalcedony, jasper, quartzite. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Modoc County
State: California
Nearest road: Fandango Pass Road
Coordinates: 41.80207, -120.20678

Geology at Fandango Pass

This spot sits on volcanic flow rocks, unit 17 (Cascade Range), mapped as andesite and basalt that formed roughly 28 to 2 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: volcanic flow rocks, unit 17 (Cascade Range)
Age: 28–2 Ma (Late Oligocene to Pleistocene)
Rock types: andesite and basalt
Elevation: 6,150 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 Fandango Pass

Best months: March to October. Typical highs run 81°F in midsummer and 35°F in midwinter, with winter lows near 18°F.

Climate normals: NOAA 1991-2020 monthlies, FT BIDWELL station (5 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

BLM California — Recreational mineral collecting
California Geological Survey
CDFW — Suction Dredge Mining Permit Program
Community submissions reviewed against published agency rules

Found at Fandango Pass

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 Fandango Pass.

Across the state line from Fandango Pass

Fandango Pass is close enough to the California border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.

Fandango Pass FAQ

Where is Fandango Pass?+

Fandango Pass is in Modoc County, California, at 41.80207, -120.20678. Nearest road: Fandango Pass Road.

What rocks and minerals can you find at Fandango Pass?+

Fandango Pass is reported to produce Agate, Chalcedony, Jasper, Quartzite.

Is collecting allowed at Fandango Pass?+

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 Fandango Pass?+

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 Fandango Pass?+

The most comfortable months at Fandango Pass are March to October.

How do I get to Fandango Pass?+

Open the directions link to navigate to 41.80207, -120.20678 in Google Maps. The nearest road is Fandango Pass Road.

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