Sugarloaf Mt.: Nephrite & Serpentine Rockhounding in Curry County, Oregon

Quick details

Access

Public area

County

Curry County

State

Oregon

Coordinates

42.83750, -124.24016

Geology at Sugarloaf Mt.

This spot sits on Sixes River Terrane, mapped as sandstone, light gray, black; chert, volcanic rock, dark gray mudstone clasts; fracture fill: pyrolusite-stained; mineralogy: lithic, feldspathic; small, angular dark gray mudstone, clasts, and siltstone that formed roughly 200 to 66 million years ago. Volcanic ground like this weathers into rocky slopes and float, and fresh exposures in cuts and drainages are usually the most productive places to look.

Mapped unit

Sixes River Terrane

Age

200–66 Ma (Jurassic to Cretaceous)

Rock types

sandstone, light gray, black; chert, volcanic rock, dark gray mudstone clasts; fracture fill: pyrolusite-stained; mineralogy: lithic, feldspathic; small, angular dark gray mudstone, clasts, and siltstone

Elevation

1,730 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 Sugarloaf Mt.

Conditions here are workable year-round, with typical highs from 49°F in winter to 73°F in summer.

Climate normals: NOAA 1991-2020 monthlies, POWERS station (9 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 Sugarloaf Mt.

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

• Nephrite
• SerpentineEncyclopedia →