Promontory Mountains: Cerussite & Bornite Rockhounding in Box Elder County, Utah
- Minerals reported
- 9
- Elevation
- 4,390 ft
- Best months
- March to June
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.
Plan your visit
Generally open to casual rockhounding
- County
- Box Elder County
- State
- Utah
- Nearest road
- South East Promontory Road
- Coordinates
- 41.25391, -112.49126
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 Promontory Mountains
Comfortable months (45 to 90°F highs)
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).
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.
Today's weather
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The app shows live weather, recent rain, and a daily rockhounding score for Promontory Mountains.
Get the appSources & 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:
- 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 name 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 PointBox Elder County, Utah · 4 mi awayObsidian, Variscite
- Great Salt LakeTooele County, Utah · 22 mi awayAragonite, Bloedite, Gypsum
- Great Salt LakeBox Elder County, Utah · 24 mi awayAragonite, Bloedite, Glauberite
- Antelope IslandDavis County, Utah · 24 mi awayGarnet, Azurite, Biotite
- Lakeside MountainsTooele County, Utah · 28 mi awayAnglesite, Cerussite, Galena
- WillardBox Elder County, Utah · 29 mi awayStibnite, Galena, Hematite
- Strongs CanyonWeber County, Utah · 30 mi awayGarnet
- Great Salt LakeDavis County, Utah · 31 mi awayAragonite, Bloedite, Glauberite
Promontory Mountains FAQ
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