Dean M. Chriss
Predators and Prey, Petroglyph, Southern Utah
(Click image to enlarge)
Petroglyphs are images that are literally "pecked" into the rock surface using a sharp stone instrument. The instrument was placed on the rock the and tapped, pecking individual dots that make up the image. This was often done on stone that had accumulated a dark coating of desert varnish to increase the visibility of the artwork. Since the desert varnish continues to accumulate after the artwork is created, it is sometimes possible to approximately determine the age of the piece by determining how much desert varnish has accumulated on the "pecked" part of the image.
The rock art present here and in other areas is irreplaceable, priceless, and fragile. Touching rock art, even lightly and only once, causes eventual staining from oils that are present in human skin. Small things have huge impacts over time that spans thousands of years. If you are fortunate enough to visit one of these places, please be extremely careful to leave it exactly as you found it.