Sylvies Canyon: Wood Opal Rockhounding in Harney County, Oregon

Quick details

Access

Public area

County

Harney County

State

Oregon

Coordinates

43.85831, -119.11369

Geology at Sylvies Canyon

This spot sits on sedimentary rocks, mapped as pumiceous tuff, tuffaceous sedimentary rocks, light gray, light brown, light yellow, and white that formed roughly 23 to 5 million years ago. Petrified wood typically comes from volcanic ash beds like the ones associated with this ground, where buried forests were slowly replaced by silica.

Mapped unit

sedimentary rocks

Age

23–5 Ma (Miocene)

Rock types

pumiceous tuff, tuffaceous sedimentary rocks, light gray, light brown, light yellow, and white

Elevation

4,400 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.

Best time to visit Sylvies Canyon

Best months: March to November. Typical highs run 88°F in midsummer and 36°F in midwinter, with winter lows near 15°F.

Climate normals: NOAA 1991-2020 monthlies, BURNS MUNI AP station (20 mi away), adjusted for elevation.

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.

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 Oregon/Washington — Rockhounding & mineral material
• Oregon Department of Geology and Mineral Industries (DOGAMI)
• Oregon Parks and Recreation Department — beach collecting rules
• Community submissions reviewed against published agency rules

Found at Sylvies Canyon

Each chip opens all spots that produce that material; the encyclopedia link opens the full ID and field guide.

• Wood OpalEncyclopedia →