Promontory Mountains: Cerussite & Bornite Rockhounding in Box Elder County, Utah

Updated June 2026

Promontory Mountains is a mapped rockhounding spot in Box Elder County, Utah. Reported finds include cerussite, bornite, calamine, chalcopyrite, gold, and more. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: Box Elder County
State: Utah
Nearest road: South East Promontory Road
Coordinates: 41.25391, -112.49126

Geology at Promontory Mountains

This spot sits on ground mapped as alluvium, colluvium, and sand that formed within roughly the last 66 million years. Stream-worked gravels like these are where placer gold tends to concentrate, settling toward bedrock, inside gravel bars, and behind boulders.

Age: 66 Ma to present (Tertiary to Quaternary)
Rock types: alluvium, colluvium, and sand
Elevation: 4,390 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 Promontory Mountains

Best months: March to June. Typical highs run 94°F in midsummer and 38°F in midwinter, with winter lows near 20°F.

Climate normals: NOAA 1991-2020 monthlies, OGDEN SUGAR FACTORY station (24 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 Promontory Mountains

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 Promontory Mountains.

Promontory Mountains FAQ

Where is Promontory Mountains?+

Promontory Mountains is in Box Elder County, Utah, at 41.25391, -112.49126. Nearest road: South East Promontory Road.

What rocks and minerals can you find at Promontory Mountains?+

Promontory Mountains is reported to produce Cerussite, Bornite, Calamine, Chalcopyrite, Gold, Gypsum, Limonite, Malachite, Pyrite.

Is collecting allowed at Promontory Mountains?+

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 Promontory Mountains?+

A gold pan, a classifier screen, a small shovel, and a snuffer bottle cover the basics. Motorized equipment and sluices fall under separate rules in most states, so start with hand tools.

When is the best time to visit Promontory Mountains?+

The most comfortable months at Promontory Mountains are March to June.

How do I get to Promontory Mountains?+

Open the directions link to navigate to 41.25391, -112.49126 in Google Maps. The nearest road is South East Promontory Road.

More rockhounding in Utah

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Open Promontory Mountains on the map

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