San Rafael Swell: Agatized Wood & Amethyst Rockhounding in Emery County, Utah

Plan your visit

Generally open to casual rockhounding

County

Emery County

State

Utah

Coordinates

38.92207, -110.53088

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.

Access note: Large BLM-managed recreation area with wilderness and special-management units nearby. Confirm collecting is allowed at the specific wash or exposure before taking material.

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 Rafael Swell

Comfortable months (45 to 90°F highs)

Best months: March to November. Typical highs run 90°F in midsummer and 36°F in midwinter, with winter lows near 12°F.

Climate normals: NOAA 1991-2020 monthlies, GOBLIN VALLEY SP station (26 mi away), adjusted for elevation.

Geology at San Rafael Swell

This spot sits on Cutler Group, mapped as sandstone that formed roughly 305 to 275 million years ago. Sedimentary beds like these are the typical host for petrified and silicified wood, which weathers out as durable float on slopes and in washes.

Mapped unit

Cutler Group

Age

305–275 Ma (Late Pennsylvanian to Cisuralian)

Rock types

sandstone

Elevation

6,240 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