Colorado River: Agate & Chalcedony Rockhounding in Grand County, Utah

Updated June 2026

Colorado River is a mapped rockhounding spot in Grand County, Utah. Reported finds include agate, chalcedony, chert, jasper, opal, and more. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Grand County
State: Utah
Nearest road: Dinosaur Diamond Prehistoric Highway
Postcode: 84532
Coordinates: 38.60268, -109.58412

Geology at Colorado River

This spot sits on ground mapped as Stream alluvium that formed within roughly the last 129,000 years. Petrified wood typically travels as tough float, and worked gravels like these are exactly where weathered pieces tend to collect.

Mapped unit: Stream alluvium
Age: < 1 Ma (Late Pleistocene to Holocene)
Elevation: 3,970 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 Colorado River

Best months: February to May. Typical highs run 99°F in midsummer and 42°F in midwinter, with winter lows near 23°F. Monsoon storms peak in July and August and can flood washes fast.

Climate normals: NOAA 1991-2020 monthlies, ARCHES NP HQS station (2 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.

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 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 Colorado River.

Colorado River FAQ

Where is Colorado River?+

Colorado River is in Grand County, Utah, at 38.60268, -109.58412. Nearest road: Dinosaur Diamond Prehistoric Highway.

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

Colorado River is reported to produce Agate, Chalcedony, Chert, Jasper, Opal, Opalized Wood, Quartz.

Is collecting allowed at 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 Colorado River?+

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 Colorado River?+

The most comfortable months at Colorado River are February to May. Monsoon storms peak in July and August and can flood washes fast.

How do I get to Colorado River?+

Open the directions link to navigate to 38.60268, -109.58412 in Google Maps. The nearest road is Dinosaur Diamond Prehistoric Highway.

More rockhounding in Utah

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Open Colorado River on the map

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