Himalaya Tourmaline Mine (Mesa Grande): Tourmaline & Lepidolite Rockhounding in San Diego County, California

Quick details

Access

Paid / fee dig

County

San Diego County

State

California

Nearest road

Porter Lane

Postcode

92036

Coordinates

33.07000, -116.60000

Geology at Himalaya Tourmaline Mine (Mesa Grande)

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

4,360 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 Himalaya Tourmaline Mine (Mesa Grande)

Conditions here are workable year-round, with typical highs from 52°F in winter to 85°F in summer.

Climate normals: NOAA 1991-2020 monthlies, JULIAN CDF station (1 mi away), adjusted for elevation.

Land & collecting status

Pay-to-dig site

This is a fee-dig location. Hours, prices, and what you can keep vary by operator. Call ahead before driving out.

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 Himalaya Tourmaline Mine (Mesa Grande)

Each chip opens all spots that produce that material; the encyclopedia link opens the full ID and field guide.

• TourmalineEncyclopedia →
• LepidoliteEncyclopedia →
• QuartzEncyclopedia →