San Juan River: Anhydrite & Chalcopyrite Rockhounding in San Juan County, Utah

Plan your visit

Permission required before collecting

County

San Juan County

State

Utah

Coordinates

37.27819, -109.41251

Coordinates are approximate. Confirm the exact ground in the RockHoundR app, where land overlays show which agency manages the area.

Land & collecting status

Permission required before collecting

Requires landowner or agency permission before any collecting. Do not enter without explicit authorization.

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 San Juan River

Comfortable months (45 to 90°F highs)

Best months: February to May. Typical highs run 96°F in midsummer and 43°F in midwinter, with winter lows near 20°F. Monsoon storms peak in July and August and can flood washes fast.

Climate normals: NOAA 1991-2020 monthlies, BLUFF station (8 mi away).

Geology at San Juan River

This spot sits on Alluvium and colluvium, mapped as unconsolidated alluvium and colluvium that formed within roughly the last 3 million years. Stream-worked gravels like these are where placer gold tends to concentrate, settling toward bedrock, inside gravel bars, and behind boulders.

Mapped unit

Alluvium and colluvium

Age

3 Ma to present (Quaternary)

Rock types

unconsolidated alluvium and colluvium

Elevation

4,370 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.

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