Where to Find Opal in Washington: 13 Mapped Sites
Washington has 13 documented sites where opal have been reported, and the best-known are Bickleton, Cairn Hope Peak, and Columbia River. Every site is mapped below with GPS coordinates and links to a full report of access and what's been found there. 13 of the 13 sites are on public-access land.
Last updated: — data compiled by the Rockhounding.org Research Team · methodology
Opal Map: Washington
All 13 opal sites in Washington. Click a pin for the full site report.
Where Opal Are Found in Washington
Opal precipitates from silica-rich groundwater in volcanic ash beds and weathered rhyolite, and famously replaces buried wood. Look along seams and cavities in altered volcanic ground.
The richest reported sites in Washington: Bickleton, Cairn Hope Peak, Columbia River, Mabton, Mondovi.
Local reporting distinguishes Opalized Wood (10 sites), Fire Opal (2 sites), Common Opal (1 site).
Of the 13 sites, 13 are public access. Check each site report for current land status before you go.
All Opal Sites in Washington
- Bickleton — Public Access
- Cairn Hope Peak — Public Access
- Columbia River — Public Access
- Mabton — Public Access
- Mondovi — Public Access
- Petrified Forest State Park — Public Access
- Rattlesnake Mt. — Public Access
- Grand Coulee — Public Access
- Horse Heaven Hills — Public Access
- Mattawa — Public Access
- Moses Coulee — Public Access
- Pullman — Public Access
- Waterville — Public Access
How to Identify Opal
Opal is hardened silica gel: hardness only 5.5–6.5, waxy-to-pearly luster, conchoidal fracture, and noticeably lighter than quartz. Precious opal flashes shifting spectral color; common opal is milky, honey, or green without fire. Field-check suspect seams with a flashlight from behind — opal transmits a soft glow. Freshly dug opal can craze as it dries, so keep finds damp.
Not sure what you found? Try our identification guide →Frequently Asked Questions
Where can I find opal in Washington?
Washington has 13 mapped sites where opal have been reported. The best-known are Bickleton, Cairn Hope Peak, and Columbia River. Each listing on the map above includes GPS coordinates, access type, and what has been found there.
How many opal sites are mapped in Washington?
We have 13 documented opal sites in Washington, compiled from community submissions and published locality records and reviewed by the Rockhounding.org Research Team.
Is it legal to collect opal in Washington?
Casual collecting is generally allowed on BLM and National Forest land for personal, non-commercial use — the standard BLM limit is 25 lbs per day plus one specimen. National parks, monuments, and many state parks prohibit collecting, and private land always requires the owner's permission. Check the site report for each location and verify current land status before you dig.
How do I identify opal?
Opal is hardened silica gel: hardness only 5.5–6.5, waxy-to-pearly luster, conchoidal fracture, and noticeably lighter than quartz. Precious opal flashes shifting spectral color; common opal is milky, honey, or green without fire. Field-check suspect seams with a flashlight from behind — opal transmits a soft glow. Freshly dug opal can craze as it dries, so keep finds damp.
What kinds of opal are found in Washington?
Reports from Washington distinguish Opalized Wood (10 sites), Fire Opal (2 sites), Common Opal (1 site).
What should I bring to collect opal?
The basics: a rock hammer, safety glasses, gloves, a bucket or padded bag for specimens, and a GPS app with the coordinates from this page. Add a spray bottle — wetting a stone makes color and banding far easier to judge in the field.
⚠️ Always verify current regulations, weather conditions, and access requirements before visiting any location. Information provided is based on community submissions and may not be current or accurate.
Data: community submissions — reviewed and approved by the Rockhounding.org Research Team. Always verify current land status, regulations, and access before visiting any site.