Centennial Cone: Aquamarine & Bertrandite Rockhounding in Jefferson County, Colorado

Updated June 2026

Centennial Cone is a mapped rockhounding spot in Jefferson County, Colorado. Reported finds include aquamarine, bertrandite, beryl, smoky quartz. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Jefferson County
State: Colorado
Nearest road: Elk Range Trail
Coordinates: 39.75542, -105.36075

Geology at Centennial Cone

This spot sits on ground mapped as Felsic gneiss that formed roughly 2500 to 1600 million years ago. Metamorphic terrain like this typically carries quartz veins and sweats, and weathered crystals tend to end up in the soils and streams below.

Mapped unit: Felsic gneiss
Age: 2500–1600 Ma (Paleoproterozoic)
Elevation: 8,140 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 Centennial Cone

Best months: March to November. Typical highs run 79°F in midsummer and 37°F in midwinter, with winter lows near 15°F. At about 8,140 ft, snow can block access from late fall well into spring, so check conditions outside of summer.

Climate normals: NOAA 1991-2020 monthlies, RALSTON RSVR station (8 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 Centennial Cone

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 Centennial Cone.

Centennial Cone FAQ

Where is Centennial Cone?+

Centennial Cone is in Jefferson County, Colorado, at 39.75542, -105.36075. Nearest road: Elk Range Trail.

What rocks and minerals can you find at Centennial Cone?+

Centennial Cone is reported to produce Aquamarine, Bertrandite, Beryl, Smoky Quartz.

Is collecting allowed at Centennial Cone?+

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 Centennial Cone?+

A rock hammer, a small pry bar, gloves, and safety glasses cover most crystal ground. A screen helps in loose pocket soil, and newspaper protects points on the way out.

When is the best time to visit Centennial Cone?+

The most comfortable months at Centennial Cone are March to November. At about 8,140 ft, snow can block access from late fall well into spring, so check conditions outside of summer.

How do I get to Centennial Cone?+

Open the directions link to navigate to 39.75542, -105.36075 in Google Maps. The nearest road is Elk Range Trail.

More rockhounding in Colorado

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Open Centennial Cone on the map

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