Monticello mining district: Anhydrite & Carnotite Rockhounding in San Juan County, Utah

Plan your visit

Generally open to casual rockhounding

County

San Juan County

State

Utah

Nearest road

Cooley Pass Trail

Coordinates

37.83127, -109.46702

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 Monticello mining district

Comfortable months (45 to 90°F highs)

Best months: April to October. Typical highs run 71°F in midsummer and 24°F in midwinter, with winter lows near 3°F. At about 10,860 ft, snow can block access from late fall well into spring, so check conditions outside of summer.

Climate normals: NOAA 1991-2020 monthlies, MONTICELLO #2 station (7 mi away), adjusted for elevation.

Geology at Monticello mining district

This spot sits on Morrison Formation (Brushy Basin and Salt Wash Members), mapped as sandstone mudstone that formed roughly 160 to 145 million years ago. Sedimentary rock like this erodes unevenly, so the most productive collecting is typically along fresh cuts, badland slopes, and active drainages.

Mapped unit

Morrison Formation (Brushy Basin and Salt Wash Members)

Age

160–145 Ma (Late Jurassic)

Rock types

sandstone mudstone

Elevation

10,860 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