Willapa Hills: Fossil Hunting in Pacific County, Washington
Updated June 2026
The Washington Geological Survey documents light-gray to yellowish-gray chalcedony casts of fossil clams in the Willapa Hills, some holding trapped water that shifts when the specimen is turned, a feature collectors call enhydros. The surrounding marine sedimentary rocks yield abundant pelecypod, gastropod, and crab fossils. The agatized shells are a distinctive Pacific County specialty. Reported finds include agatized fossil shells. Below: coordinates, access notes, nearby spots, and trip-planning links.
Willapa Hills photos
Public image records connected to this spot or its reported material.
Map showing Willapa Hills in Pacific County, Washington
Quick details
- Access
- Public area
- County
- Pacific County
- State
- Washington
- Coordinates
- 46.66697, -123.50191
Geology at Willapa Hills
This spot sits on Astoria Formation, Rotalia becki zone (Luisian?), mapped as marine sedimentary rocks that formed roughly 23 to 5 million years ago. Sedimentary layers like these are where fossils are typically preserved, and fresh exposures after rain or in active cuts tend to produce best.
- Mapped unit
- Astoria Formation, Rotalia becki zone (Luisian?)
- Age
- 23–5 Ma (Miocene)
- Rock types
- marine sedimentary rocks
- Elevation
- 160 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 Willapa Hills
Conditions here are workable year-round, with typical highs from 47°F in winter to 71°F in summer.
Climate normals: NOAA 1991-2020 monthlies, RAYMOND 2 S station (11 mi away).
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:
- Washington Geological Survey (DNR)
- Stonerose Interpretive Center — Visit & rules
- BLM Spokane District
- Community submissions reviewed against published agency rules
Found at Willapa Hills
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 Willapa Hills.
- Green CreekPacific County, Washington · 8 mi awayAgate, Carnelian, Chalcedony
- LebamPacific County, Washington · 8 mi awayAgatized Fossil Shells, Chalcedony
- DotyLewis County, Washington · 11 mi awayAgate, Carnelian, Chalcedony
- Pe EllTop pick in WashingtonLewis County, Washington · 11 mi awayAgate, Carnelian, Chalcedony
- McCoy Farm near AdnaLewis County, Washington · 17 mi awayCarnelian, Petrified Wood
- CentraliaLewis County, Washington · 27 mi awayAgate, Carnelian, Chalcedony
- Ocean ParkPacific County, Washington · 29 mi awayAgate, Chalcedony, Quartz
- Newaukum River gravelsLewis County, Washington · 31 mi awayGeode, Nodules
Across the state line from Willapa Hills
Willapa Hills is close enough to the Washington border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.
- Pacific Ocean beachesClatsop County, Oregon · 42 mi awayBloodstone, Jasper, Agate
- Nehalem River gravelsClatsop County, Oregon · 54 mi awayAgate, Carnelian, Jasper
- Clear CreekColumbia County, Oregon · 61 mi awayPlume Agate, Carnelian, Jasper
- Columbia River shoreColumbia County, Oregon · 69 mi awayThomsonite
- Ocean beachTillamook County, Oregon · 70 mi awayAgate, Jasper, Bloodstone
- Wilson RiverTop pick in OregonTillamook County, Oregon · 75 mi awayAgate, Carnelian, Jasper
Willapa Hills FAQ
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