Alta: Apatite & Biotite Rockhounding in Salt Lake County, Utah

Plan your visit

Generally open to casual rockhounding

County

Salt Lake County

State

Utah

Nearest road

Flagstaff Mountain Trail

Postcode

84138

Coordinates

40.59661, -111.63740

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 Alta

Comfortable months (45 to 90°F highs)

Best months: May to October. Typical highs run 70°F in midsummer and 28°F in midwinter, with winter lows near 12°F. At about 9,480 ft, snow can block access from late fall well into spring, so check conditions outside of summer.

Climate normals: NOAA 1991-2020 monthlies, ALTA station (0 mi away), adjusted for elevation.

Geology at Alta

This spot sits on ground mapped as Maxfield Limestone that formed roughly 510 to 495 million years ago. Carbonate rock like this is the classic host for lead, zinc, and fluorite mineralization, which typically follows old cavities and replacement zones.

Mapped unit

Maxfield Limestone

Age

510–495 Ma (Middle Cambrian)

Elevation

9,480 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