Kelso: Agate Rockhounding in Cowlitz County, Washington

Updated June 2026

Kelso is a mapped rockhounding spot in Cowlitz County, Washington. Reported finds include agate. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Cowlitz County
State: Washington
Nearest road: I 5
Postcode: 98609
Coordinates: 46.06721, -122.86771

Geology at Kelso

This spot sits on Goble Volcanics, mapped as andesite flows 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: Goble Volcanics
Age: 56–23 Ma (Eocene to Oligocene)
Rock types: andesite flows
Elevation: 90 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 Kelso

Conditions here are workable year-round, with typical highs from 47°F in winter to 79°F in summer.

Climate normals: NOAA 1991-2020 monthlies, LONGVIEW station (7 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: April 1, 2026

Washington Geological Survey (DNR)
Stonerose Interpretive Center — Visit & rules
BLM Spokane District
Community submissions reviewed against published agency rules

Found at Kelso

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

Agate Encyclopedia →

Nearby rockhounding spots

Other rockhounding spots within driving distance of Kelso.

Across the state line from Kelso

Kelso 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.

Kelso FAQ

Where is Kelso?+

Kelso is in Cowlitz County, Washington, at 46.06721, -122.86771. Nearest road: I 5.

What rocks and minerals can you find at Kelso?+

Kelso is reported to produce Agate.

Is collecting allowed at Kelso?+

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 Kelso?+

Most agate and jasper is surface float: bring a spray bottle, a pick or small shovel, and a sturdy bag. Wet stones show their banding and translucence.

When is the best time to visit Kelso?+

Kelso is workable year-round.

How do I get to Kelso?+

Open the directions link to navigate to 46.06721, -122.86771 in Google Maps. The nearest road is I 5.

More rockhounding in Washington

See all 92 Washington spots →

Open Kelso on the map

Use the RockHoundR app for live land overlays, weather, geology, directions, and saved finds.