Desolation Canyon: Thundereggs Rockhounding in Crook County, Oregon

Quick details

Access

Permission required

County

Crook County

State

Oregon

Coordinates

44.47571, -120.50740

Geology at Desolation Canyon

This spot sits on John Day/Clarno Group; John Day Formation, mapped as rhyolite intrusives that formed roughly 56 to 23 million years ago. 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

John Day/Clarno Group; John Day Formation

Age

56–23 Ma (Eocene to Oligocene)

Rock types

rhyolite intrusives

Elevation

4,400 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 Desolation Canyon

Best months: March to November. Typical highs run 79°F in midsummer and 39°F in midwinter, with winter lows near 22°F.

Climate normals: NOAA 1991-2020 monthlies, MITCHELL 2 E station (20 mi away), adjusted for elevation.

Land & collecting status

Permission required before collecting

Requires landowner or agency permission before any collecting. Do not enter without explicit authorization.

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 Oregon/Washington — Rockhounding & mineral material
• Oregon Department of Geology and Mineral Industries (DOGAMI)
• Oregon Parks and Recreation Department — beach collecting rules
• Community submissions reviewed against published agency rules

Found at Desolation Canyon

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

• ThundereggsEncyclopedia →