“ ...This claim is privately owned and is located in the Mill Creek drainage. The bed has only been dug sporadically by a friend of the landowner. From what I have heard, it has been at least 4 years since any new specimens have come out of this location, so they are becoming scarce.
The Fred Bed thundereggs are very unusual looking for Ochoco Mountain eggs, they have a very smooth, aphanitic matrix that ranges from a light tan on the outside to various shades of brown and tan on the inside. The agate within can range from white to blue to brown and even black. Moss and tubes, as well as calcite crystals, are common occurrences...”
extract of the article from Mark Ketsdever, Hillsboro, Oregon, 2007 :”Thunderegg Agates of the Ochoco Mountains, Oregon, USA”