Fairfield: Chalcedony & Chert Rockhounding in Utah County, Utah

Plan your visit

Generally open to casual rockhounding

County

Utah County

State

Utah

Nearest road

Lewiston Road

Coordinates

40.27360, -112.14522

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 Fairfield

Comfortable months (45 to 90°F highs)

Best months: March to November. Typical highs run 89°F in midsummer and 38°F in midwinter, with winter lows near 12°F.

Climate normals: NOAA 1991-2020 monthlies, FAIRFIELD station (3 mi away), adjusted for elevation.

Geology at Fairfield

This spot sits on Alluvium and colluvium, mapped as unconsolidated alluvium and colluvium 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

Alluvium and colluvium

Age

3 Ma to present (Quaternary)

Rock types

unconsolidated alluvium and colluvium

Elevation

5,340 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