Mine Dumps (San Diego Co.): Aquamarine & Beryl Rockhounding in San Diego County, California

Updated June 2026

Mine Dumps (San Diego Co.) is a mapped rockhounding spot in San Diego County, California. Reported finds include aquamarine, beryl, lepidolite, quartz, smoky quartz. Below: coordinates, access notes, nearby spots, and trip-planning links.

Quick details

Access: Public area
County: San Diego County
State: California
Nearest road: Highway 76
Coordinates: 33.23547, -116.75911

Geology at Mine Dumps (San Diego Co.)

This spot sits on pre-Cenozoic granitic and metamorphic rocks undivided, mapped as plutonic and gneiss that formed roughly 2500 to 66 million years ago. Granitic ground like this typically carries quartz veins and pockets, and weathered crystals tend to collect in the soils and drainages below.

Mapped unit: pre-Cenozoic granitic and metamorphic rocks undivided
Age: 2500–66 Ma (Paleoproterozoic to Late Cretaceous)
Rock types: plutonic and gneiss
Elevation: 2,780 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 Mine Dumps (San Diego Co.)

Best months: September to June. Typical highs run 92°F in midsummer and 60°F in midwinter, with winter lows near 31°F.

Climate normals: NOAA 1991-2020 monthlies, HENSHAW DAM station (0 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 California — Recreational mineral collecting
California Geological Survey
CDFW — Suction Dredge Mining Permit Program
Community submissions reviewed against published agency rules

Found at Mine Dumps (San Diego Co.)

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 Mine Dumps (San Diego Co.).

Mine Dumps (San Diego Co.) FAQ

Where is Mine Dumps (San Diego Co.)?+

Mine Dumps (San Diego Co.) is in San Diego County, California, at 33.23547, -116.75911. Nearest road: Highway 76.

What rocks and minerals can you find at Mine Dumps (San Diego Co.)?+

Mine Dumps (San Diego Co.) is reported to produce Aquamarine, Beryl, Lepidolite, Quartz, Smoky Quartz.

Is collecting allowed at Mine Dumps (San Diego Co.)?+

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 Mine Dumps (San Diego Co.)?+

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 Mine Dumps (San Diego Co.)?+

The most comfortable months at Mine Dumps (San Diego Co.) are September to June.

How do I get to Mine Dumps (San Diego Co.)?+

Open the directions link to navigate to 33.23547, -116.75911 in Google Maps. The nearest road is Highway 76.

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Open Mine Dumps (San Diego Co.) on the map

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