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

Plan your visit

Generally open to casual rockhounding

County

Grand County

State

Utah

Nearest road

CR 176

Postcode

84515

Coordinates

38.96876, -109.26232

Coordinates are approximate. Confirm the exact ground in the RockHoundR app, where land overlays show which agency manages the area.

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.

Best time to visit Hills by Colorado River

Comfortable months (45 to 90°F highs)

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.

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.

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