Best spot

Medora: Agate & Chalcedony Rockhounding in Billings County, North Dakota

Updated July 2026

Medora sits in the badlands of Billings County, ringed by the Little Missouri National Grassland where the Forest Service permits casual collection of petrified wood, agate, and chalcedony. The surrounding Bullion Creek and Sentinel Butte formations weather out silicified wood and chalcedony across the buttes and draws. Collecting is prohibited within the adjacent Theodore Roosevelt National Park, so the grassland tracts outside the park boundary are the legal ground. Reported finds include agate, chalcedony, silicified wood. Below: coordinates, access notes, nearby spots, and trip-planning links.

Medora photos

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

1 photo

Badlands at Painted Canyon near Medora, Billings County, North Dakota

Quick details

Access: Permission required
County: Billings County
State: North Dakota
Nearest road: I 94
Postcode: 58645
Coordinates: 46.92326, -103.49210

Geology at Medora

This spot sits on Bullion Creek Formation, mapped as claystone and siltstone 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: Bullion Creek Formation
Age: 66–56 Ma (Paleocene)
Rock types: claystone and siltstone
Elevation: 2,590 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 Medora

Best months: April to October. Typical highs run 84°F in midsummer and 26°F in midwinter, with winter lows near 2°F.

Climate normals: NOAA 1991-2020 monthlies, MEDORA station (2 mi away), adjusted for elevation.

Land & collecting status

Permission required before collecting

Requires landowner or agency permission before any collecting. Do not enter without explicit authorization.

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 Medora

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 Medora.

Across the state line from Medora

Medora is close enough to the North Dakota border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.

Medora FAQ

Where is Medora?+

Medora is in Billings County, North Dakota, at 46.92326, -103.49210. Nearest road: I 94.

What rocks and minerals can you find at Medora?+

Medora is reported to produce Agate, Chalcedony, Silicified Wood.

Is collecting allowed at Medora?+

Permission required before collecting. Requires landowner or agency permission before any collecting. Do not enter without explicit authorization. Always confirm current rules with the managing agency before a trip.

What tools should I bring to Medora?+

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 Medora?+

The most comfortable months at Medora are April to October.

How do I get to Medora?+

Open the directions link to navigate to 46.92326, -103.49210 in Google Maps. The nearest road is I 94.

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