Lucky Strike Mine: Thundereggs Rockhounding in Crook County, Oregon

Quick details

Access

Paid / fee dig

County

Crook County

State

Oregon

Nearest road

Forest Road 2730-200

Coordinates

44.51794, -120.49606

Geology at Lucky Strike Mine

This spot sits on John Day/Clarno Group; Clarno Formation, mapped as intrusives, plagioclase clinopyroxene orthopyroxene or hornblened less olivine phenocrysts; lithology: basaltic andesite andesite bit range from olivine basalt to dacite, volcanic breccia, angular to subangular andesite basalt fragments fragments; lithology: basaltic andesite andesite bit range from olivine basalt to dacite; matrix: andesite basalt freshly erupted ash, mafic flows, lithology: basaltic andesite andesite bit range from olivine basalt to dacite, andesite flows, and basalt flows 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; Clarno Formation

Age

56–23 Ma (Eocene to Oligocene)

Rock types

intrusives, plagioclase clinopyroxene orthopyroxene or hornblened less olivine phenocrysts; lithology: basaltic andesite andesite bit range from olivine basalt to dacite, volcanic breccia, angular to subangular andesite basalt fragments fragments; lithology: basaltic andesite andesite bit range from olivine basalt to dacite; matrix: andesite basalt freshly erupted ash, mafic flows, lithology: basaltic andesite andesite bit range from olivine basalt to dacite, andesite flows, and basalt flows

Elevation

4,900 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 Lucky Strike Mine

Best months: March to October. Typical highs run 77°F in midsummer and 37°F in midwinter, with winter lows near 20°F.

Climate normals: NOAA 1991-2020 monthlies, MITCHELL 2 E station (19 mi away), adjusted for elevation.

Land & collecting status

Pay-to-dig site

This is a fee-dig location. Hours, prices, and what you can keep vary by operator. Call ahead before driving out.

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 Lucky Strike Mine

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

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