Sorry - couldn't post last night. I'm an electrician, and 9 to 5 isn't my norm. Here are a few pictures that were on my phone. The pictures we believe to be mammoths are on my girlfriend's phone. She will be home around 10:00 PDST, so will post them by a.m.
Before you get upset look up portable rock art websites if you already haven’t. Look at what others post and how hard it is to see what they say it represents.
Not out of the woodwork, this is artifact forum and many of us have been hunting and collecting artifacts for decades, I started in 1983 and many here have been doing so longer than I.
There's a learning curve involved with most collectables, and certainly Native American artifacts are no exception. The original poster just has to do the homework required to know what such artifacts look like in his neck of the woods, and learn as well how to distinguish rocks from artifacts. These are obvious rocks. That is not really our fault. Not the OP's fault either, they are just what they are, rocks. Nobody is doing anything wrong in simply pointing out the truth of the matter. I struggle to understand why stating the truth is "amazing", or why doing so would be described as "coming out of the woodwork". That's not fair to the experienced people here who are trying to help people.
Just to help you out, these are California artifacts. Quite a few of these are from the Great Basin area and some from around Sacrameto. Concentrate on looking for these types and stay away from the Hardstone pieces until you learn true artifacts.
I've had these kicking around the shop for years. Brought 'em home because they were amusing, and I've puzzled over just how they were formed, but I never considered them artifacts, nor would I try to fool myself into believing that I'd found a Squidward or bedpan effigy.