CAIRNS AND FACADES:
A cairn is a stack of stones without debris and or dirt, just stones. There is NO geological process which produces clean stacks of rocks free of debris and dirt. An archeologist, Bill Donato, first told me of this and I verified it later in a physical geology course.
The Shasta Valley rock structures most often include lots of andesite, a rock which is resistant to chemical weathering. The good condition of the Shasta Valley structures and the public access to many of them makes Shasta an ideal place to physically examine these ancient structures. The best cairns in the Shasta Valley are at the Shasta Wildlife Area.
The Sutter Buttes are privately owned and has very limited access for the general public.