Best spot

Richardton: Agate & Chalcedony Rockhounding in Stark County, North Dakota

Updated July 2026

Richardton sits in the gravels of Stark County at the eastern edge of the Little Missouri badlands collecting country, where the Bullion Creek and Sentinel Butte formations shed agate, chalcedony, agatized wood, jasper, and blades of selenite. The material weathers from buttes, road cuts, and stream gravels across the area. Nearby national grassland tracts are open to USFS casual collecting, while surrounding farmland is private and requires permission. Reported finds include agate, chalcedony, agatized wood, jasper, selenite. Below: coordinates, access notes, nearby spots, and trip-planning links.

Richardton photos

Public image records connected to this spot or its reported material.

1 photo

Assumption Abbey, the twin-spired Benedictine abbey church in Richardton, Stark County, North Dakota

Quick details

Access: Public area
County: Stark County
State: North Dakota
Nearest road: 42nd Street Southwest
Coordinates: 46.80314, -102.30975

Geology at Richardton

This spot sits on Sentinel Butte Formation, mapped as siltstone, claystone, and sandstone that formed roughly 66 to 56 million years ago. Sedimentary beds like these are the typical host for petrified and silicified wood, which weathers out as durable float on slopes and in washes.

Mapped unit: Sentinel Butte Formation
Age: 66–56 Ma (Paleocene)
Rock types: siltstone, claystone, and sandstone
Elevation: 2,350 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 Richardton

Best months: April to October. Typical highs run 83°F in midsummer and 24°F in midwinter, with winter lows near 8°F.

Climate normals: NOAA 1991-2020 monthlies, RICHARDTON ABBEY station (6 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.

Sources: RockHoundR public spot dataset, app land overlays, and local agency review before each trip.

Found at Richardton

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 Richardton.

Richardton FAQ

Where is Richardton?+

Richardton is in Stark County, North Dakota, at 46.80314, -102.30975. Nearest road: 42nd Street Southwest.

What rocks and minerals can you find at Richardton?+

Richardton is reported to produce Agate, Chalcedony, Agatized Wood, Jasper, Selenite.

Is collecting allowed at Richardton?+

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 Richardton?+

A rock hammer, sturdy gloves, and a padded bag cover petrified wood hunting. Most pieces are surface float, so walking slopes and washes beats digging.

When is the best time to visit Richardton?+

The most comfortable months at Richardton are April to October.

How do I get to Richardton?+

Open the directions link to navigate to 46.80314, -102.30975 in Google Maps. The nearest road is 42nd Street Southwest.

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