Well, if it's on the Internet ...

then it must be true. Right?

The Mystery of Snakehead Point: An Ancient Power Center?

Found while looking for the answer to the 'Google search diary challenge' as mentioned on "An American River Canyon 'Book of Days'".

Russell had the following to say about "The Pyramid":

Another Green Valley rumor which is amazingly widespread, concerns a supposed pyramid. Aliens from outer space, it seems, had taught humans to build pyramids. The two oldest human structures in California are pyramids, one in the Owens Valley, one in Green Valley. I met adherents of this fabulous concept decades ago, and they pointed out a certain knoll of serpentine in the west end of Green Valley, a little north of the river. That the spot is beautiful, that is has a lovely view of Lovers Leap and Giant Gap, that the light of the setting sun when near the winter soldtice, just kisses this bedrock knoll, I cannot deny. That it is any kind of pyramid I do deny. Nevertheless, I call it The Pyramid. There is magic and mystery in Green Valley, just not the sort these flying-saucer mystics want to find there.

It seems that the source of this Green Valley Pyramid rumor was one Dr. Wallace Halsey, who formed a sect called the Christian Brotherhood, in the 1950s. Adding results, it would seem that Jesus himself zoomed around in flying saucers (occasionally visiting Green Valley). Halsey's description of the Green Valley Pyramid would place it on the south side of the river at the Hayden Hill mine, where another lovely knoll perches above the general level of Green Valley.

The Rural Mysteries of the North Fork Polygon folk have a dedicated page: The Pyramid of Green Valley