The Cougar Trap Bed, located in Malheur County, Oregon, is a striking thunderegg site known for producing nodules with bold, high-contrast interiors. Eggs from this location often contain richly colored agate—deep reds, oranges, and purples—frequently accented with mossy or sagenitic inclusions. The rhyolite matrix is usually dense and tan to reddish, with eggs ranging from small to large, often well-formed and solid. Cougar Trap material is especially popular among lapidary artists due to its strong visual patterns and polish-friendly composition, making it a standout among southeastern Oregon’s many thunderegg sources.
Rocks of the Cascades – Thundereggs, Tools & Tradition