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Del Norte Thunder Egg Beds: Plume Agate & Moss Agate Rockhounding in Saguache County, Colorado

Updated June 2026

The thunderegg beds northwest of Del Norte have yielded plume and moss agate from rhyolite flows since the late 1800s, with chalcedony, common opal, and quartz-lined cavities documented at the locality. The beds lie on Rio Grande National Forest and adjacent BLM land at the south end of the La Garita Mountains. Plume agate is the signature material. Reported finds include plume agate, moss agate, chalcedony, common opal, quartz. Below: coordinates, access notes, nearby spots, and trip-planning links.

Del Norte Thunder Egg Beds photos

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

1 photo

Plume agate inside a thunderegg, the kind of agate found in the Del Norte beds

Quick details

Access: Public area
County: Saguache County
State: Colorado
Coordinates: 37.76147, -106.44808

Geology at Del Norte Thunder Egg Beds

This spot sits on Pre-ash-flow andesitic lavas, breccias, tuffs, and conglomerates, mapped as andesite that formed roughly 38 to 28 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: Pre-ash-flow andesitic lavas, breccias, tuffs, and conglomerates
Age: 38–28 Ma (Late Eocene to Early Oligocene)
Rock types: andesite
Elevation: 8,830 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 Del Norte Thunder Egg Beds

Best months: March to November. Typical highs run 77°F in midsummer and 31°F in midwinter, with winter lows near 4°F. At about 8,830 ft, snow can block access from late fall well into spring, so check conditions outside of summer.

Climate normals: NOAA 1991-2020 monthlies, DEL NORTE 3ENE station (9 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.

Sources: RockHoundR public spot dataset, app land overlays, and local agency review before each trip.

Found at Del Norte Thunder Egg Beds

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 Del Norte Thunder Egg Beds.

Del Norte Thunder Egg Beds FAQ

Where is Del Norte Thunder Egg Beds?+

Del Norte Thunder Egg Beds is in Saguache County, Colorado, at 37.76147, -106.44808.

What rocks and minerals can you find at Del Norte Thunder Egg Beds?+

Del Norte Thunder Egg Beds is reported to produce Plume Agate, Moss Agate, Chalcedony, Common Opal, Quartz.

Is collecting allowed at Del Norte Thunder Egg Beds?+

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 Del Norte Thunder Egg Beds?+

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 Del Norte Thunder Egg Beds?+

The most comfortable months at Del Norte Thunder Egg Beds are March to November. At about 8,830 ft, snow can block access from late fall well into spring, so check conditions outside of summer.

How do I get to Del Norte Thunder Egg Beds?+

Open the directions link to navigate to 37.76147, -106.44808 in Google Maps. Some spots are remote, so check road conditions before driving out.

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