These look Native American to me. They appear to be cut in with iron or metal tools, not pecked. It's hard to tell without seeing seeing it first hand. This puts it around transition period after first contact ( assuming this is in North America). No Initials, or dates usually means not white folks. This is a nice site. What part of the world are you in?
Chalking will wear these down a bit. I like to use talcum powder mixed with water to the consistency of white paint. Then you can take an artist brush and fill in the marks. This will photograph really well and easily washes away. You do have a lot of initials on these other sites. Seems to be pre and post contact. That last image could almost be called an Atl Atl. Cool and old.