Big Diggins Mine: Agate Rockhounding in Luna County, New Mexico

Quick details

Access

Paid / fee dig

County

Luna County

State

New Mexico

Nearest road

County Road C018

Coordinates

32.04592, -107.94333

Geology at Big Diggins Mine

This spot sits on Piedmont alluvial deposits, mapped as unconsolidated alluvium that formed within roughly the last 3 million years. Gravels like these concentrate whatever survives the river: agate, jasper, and other tough silica typically show up as rounded, waxy stones.

Mapped unit

Piedmont alluvial deposits

Age

3 Ma to present (Pleistocene to Holocene)

Rock types

unconsolidated alluvium

Elevation

4,450 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 Big Diggins Mine

Best months: September to May. Typical highs run 96°F in midsummer and 57°F in midwinter, with winter lows near 29°F. Summer heat here is intense, so carry more water than you think you need and work the early morning.

Climate normals: NOAA 1991-2020 monthlies, GAGE station (15 mi away).

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

• Rockhound State Park — Collection rules
• BLM New Mexico
• New Mexico Bureau of Geology and Mineral Resources
• Community submissions reviewed against published agency rules

Found at Big Diggins Mine

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

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