Harvey Creek: Thundereggs Rockhounding in Crook County, Oregon

Updated June 2026

Harvey Creek is a mapped rockhounding spot in Crook County, Oregon. Reported finds include thundereggs. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Crook County
State: Oregon
Nearest road: Mill Creek Road
Coordinates: 44.45784, -120.59684

Geology at Harvey Creek

This spot sits on John Day/Clarno Group; Clarno Formation, mapped as basalt flows, tuff, andesite flows, and mudflow 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: basalt flows, tuff, andesite flows, and mudflow
Elevation: 3,940 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 Harvey Creek

Best months: March to November. Typical highs run 83°F in midsummer and 39°F in midwinter, with winter lows near 21°F.

Climate normals: NOAA 1991-2020 monthlies, PRINEVILLE station (16 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 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 Harvey Creek

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

Thundereggs Encyclopedia →

Nearby rockhounding spots

Other rockhounding spots within driving distance of Harvey Creek.

Harvey Creek FAQ

Where is Harvey Creek?+

Harvey Creek is in Crook County, Oregon, at 44.45784, -120.59684. Nearest road: Mill Creek Road.

What rocks and minerals can you find at Harvey Creek?+

Harvey Creek is reported to produce Thundereggs.

Is collecting allowed at Harvey Creek?+

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 Harvey Creek?+

A rock hammer, sturdy gloves, safety glasses, and a collecting bag cover the basics here. Add a spray bottle: wet rock shows color and pattern that dry rock hides.

When is the best time to visit Harvey Creek?+

The most comfortable months at Harvey Creek are March to November.

How do I get to Harvey Creek?+

Open the directions link to navigate to 44.45784, -120.59684 in Google Maps. The nearest road is Mill Creek Road.

More rockhounding in Oregon

See all 177 Oregon spots →

Open Harvey Creek on the map

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