Tongue River: Fossil Hunting in Pembina County, North Dakota

Updated June 2026

Tongue River is a mapped rockhounding spot in Pembina County, North Dakota. Reported finds include calcite, fossils. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Pembina County
State: North Dakota
Nearest road: Central Avenue
Coordinates: 48.73992, -97.93185

Geology at Tongue River

This spot sits on Niobrara Formation, mapped as shale that formed roughly 100 to 66 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: Niobrara Formation
Age: 100–66 Ma (Late Cretaceous)
Rock types: shale
Elevation: 1,160 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 Tongue River

Best months: April to October. Typical highs run 77°F in midsummer and 12°F in midwinter, with winter lows near -5°F.

Climate normals: NOAA 1991-2020 monthlies, CAVALIER 7NW station (13 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.

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

Found at Tongue River

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 Tongue River.

Tongue River FAQ

Where is Tongue River?+

Tongue River is in Pembina County, North Dakota, at 48.73992, -97.93185. Nearest road: Central Avenue.

What rocks and minerals can you find at Tongue River?+

Tongue River is reported to produce Calcite, Fossils.

Is collecting allowed at Tongue River?+

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 Tongue River?+

A rock hammer, a cold chisel, safety glasses, and newspaper or foam for wrapping finds cover most fossil ground. A trowel and a sieve help in soft exposures.

When is the best time to visit Tongue River?+

The most comfortable months at Tongue River are April to October.

How do I get to Tongue River?+

Open the directions link to navigate to 48.73992, -97.93185 in Google Maps. The nearest road is Central Avenue.

More rockhounding in North Dakota

See all 20 North Dakota spots →

Open Tongue River on the map

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