I first saw these pictographs more than 50 years ago. Since that time they have faded quite a bit, and have suffered some vandalism. I think that you will agree with me that the site is pretty cool.
I wonder where the pictographs might be?
Yes, that is a mortero (mortar) in the foreground. In this case however, it is likely to be ceremonial in nature, rather than for preparing food (or maybe used for both).
This is a pretty cool boulder. Right?
For scale.
Not much to see with the naked eye.
I believe that the symbol in the middle is a stylized human (anthropomorphic)

The rest of the photos have been enhanced a bit with DStretch.
A nice little sunburst and what looks like initials and phone number. That part sucks.
See the number in bottom middle of the photo? At least I think it's a number.
This site might not be visible at all (to the naked eye) for much longer. This is part of my problem with "saving these sites for future generations." Pretty soon, there will be nothing to see. It's time to figure out ways to share some of these sites, while still protecting them from vandals, and unintentional damage by viewers.