Denio Nevada is in Humboldt County near the Bilk Creek Mountains, a narrow range of peaks just south of the Oregon border and immediately southeast of Denio in the Northern Great Basin. Many years ago, the agate that came from this area, was pretty much black and white. It was simply called Denio Dendritic Agate. Now the mine is yielding an amethystine like agate that has been called Amethyst Sage. It is a very beautiful agate with purples, whites, grays and of course the black bushes.