Geology header
Geologic sightseeing

Gems and Minerals in Oregon

Learn more about Oregon's geology


The thunderegg is a structure
created in welded tuff or perlitic rocks

Gems and Minerals in Oregon

Thunderegg sites

Desolation Canyon Thundereggs
Desolation Canyon Thundereggs came from high in the Ochoco Mt's of Central Oregon north east of Prineville. All deposits are now in a strict area called Mill Creek Wilderness area and now closed to collecting.

This deposit is near the Oregon/Nevada Border. Near a town called McDermitt in Humbolt County. There are several Thunderegg deposits within this area. We know of 2 types - the Quinn River deposit and the Calico Deposit. We also have a red and yellow saginite from this area.

Steins Pillar Thundereggs
On your way south down Mill Creek Canyon is a geological formation known as Steins Pillar. Many years ago in the area around this formation there were some small thunderegg deposits.

Succor Creek
This deposit is in the far eastern part of Oregon almost on the border with Idaho. this was and is a very large deposit of Thundereggs. These thundereggs can get large as in excess of hundreds of pounds! But most are average sized up to grapefruit sized. Interesting specimens, but not much color. they are mostly a clear and white agate mix.

Home | Publications Center | Hazards | Permits | About | Search

Fossils, Minerals & Gems | Hazards | News and Events
State of Oregon website | Job listings from the State of Oregon jobs page

Oregon Department of Geology and Mineral Industries
800 NE Oregon Street, Suite 965, Portland, OR 97232-2162
971-673-1555, FAX 971-673-1562
email us at DOGAMI