Eagle Rock: Plume Agate & Moss Agate Rockhounding in Crook County, Oregon

Quick details

Access

Check locally

County

Crook County

State

Oregon

Nearest road

Paulina Highway

Coordinates

44.19634, -120.65244

Geology at Eagle Rock

This spot sits on John Day/Clarno Group; John Day Formation, mapped as ash-flow tuff that formed roughly 56 to 23 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

John Day/Clarno Group; John Day Formation

Age

56–23 Ma (Eocene to Oligocene)

Rock types

ash-flow tuff

Elevation

3,610 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 Eagle Rock

Best months: February to November. Typical highs run 84°F in midsummer and 41°F in midwinter, with winter lows near 22°F.

Climate normals: NOAA 1991-2020 monthlies, PRINEVILLE station (12 mi away), adjusted for elevation.

Land & collecting status

Confirm rules before collecting

Land status here is not confirmed. Verify with the managing agency before collecting — federal, state, and tribal rules differ.

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 Eagle Rock

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

• Plume AgateEncyclopedia →
• Moss AgateEncyclopedia →
• JasperEncyclopedia →