West Side Warner Peak: Geode Digging in Lake County, Oregon

Quick details

Access

Permission required

County

Lake County

State

Oregon

Coordinates

42.46724, -119.78187

Geology at West Side Warner Peak

This spot sits on volcanic rocks; Warner Peak Volcanics, mapped as basaltic trachyandesite flows, black, and dark gray; autobrecciated clasts; vesicle fill: chalcedony opal calcite zeolites (stilbite); plagioclase clinopyroxene olivine fe-ti oxides apatite phenocrysts that formed roughly 34 to 5 million years ago. Volcanic rock like this is classic geode and thunderegg country: gas cavities in the old flows can line themselves with quartz or agate over time.

Mapped unit

volcanic rocks; Warner Peak Volcanics

Age

34–5 Ma (Oligocene to Miocene)

Rock types

basaltic trachyandesite flows, black, and dark gray; autobrecciated clasts; vesicle fill: chalcedony opal calcite zeolites (stilbite); plagioclase clinopyroxene olivine fe-ti oxides apatite phenocrysts

Elevation

5,500 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 West Side Warner Peak

Best months: March to November. Typical highs run 84°F in midsummer and 41°F in midwinter, with winter lows near 22°F.

Climate normals: NOAA 1991-2020 monthlies, HART MTN REFUGE station (9 mi away).

Land & collecting status

Permission required before collecting

Requires landowner or agency permission before any collecting. Do not enter without explicit authorization.

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 West Side Warner Peak

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

• AgateEncyclopedia →
• ChalcedonyEncyclopedia →
• GeodeEncyclopedia →
• JasperEncyclopedia →
• OpalEncyclopedia →
• ThundereggsEncyclopedia →