“ ... Harper Blackskin thundereggs look very similar to Skull Springs and Buchanan Varieties. Found near Harper in Malheur County, Oregon, the name comes from the black surface of the skin. Red Skin and green skin eggs are also found in the area. It is reported, that at least six other little-known beds are in the same area... “

From the presentation-programm “These Fabulous Thundereggs”, published by Doug Moore, Stevens Point, 2005