Hills by Colorado River: Fossil Hunting in Grand County, Utah

Updated June 2026

Hills by Colorado River is a mapped rockhounding spot in Grand County, Utah. Reported finds include agatized clams, agatized dinosaur bone, jasperized dinosaur bone, jasper. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Grand County
State: Utah
Nearest road: CR 176
Postcode: 84515
Coordinates: 38.96876, -109.26232

Geology at Hills by Colorado River

This spot sits on ground mapped as Dakota Sandstone that formed roughly 100 to 94 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: Dakota Sandstone
Age: 100–94 Ma (Late Cretaceous)
Elevation: 4,430 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 Hills by Colorado River

Best months: February to May. Typical highs run 100°F in midsummer and 41°F in midwinter, with winter lows near 15°F. Summer heat here is intense, so carry more water than you think you need and work the early morning.

Climate normals: NOAA 1991-2020 monthlies, DEWEY station (11 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.

State guidance last verified: April 1, 2026

BLM Utah — Rockhounding overview
Utah Geological Survey — collecting guidelines
SITLA — surface use rules
Community submissions reviewed against published agency rules

Found at Hills by Colorado 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 Hills by Colorado River.

Hills by Colorado River FAQ

Where is Hills by Colorado River?+

Hills by Colorado River is in Grand County, Utah, at 38.96876, -109.26232. Nearest road: CR 176.

What rocks and minerals can you find at Hills by Colorado River?+

Hills by Colorado River is reported to produce Agatized Clams, Agatized Dinosaur Bone, Jasperized Dinosaur Bone, Jasper.

Is collecting allowed at Hills by Colorado 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 Hills by Colorado 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 Hills by Colorado River?+

The most comfortable months at Hills by Colorado River are February to May. Summer heat here is intense, so carry more water than you think you need and work the early morning.

How do I get to Hills by Colorado River?+

Open the directions link to navigate to 38.96876, -109.26232 in Google Maps. The nearest road is CR 176.

More rockhounding in Utah

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Open Hills by Colorado River on the map

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