Petroglyphs are designs made by carving or scratching away the dark layer of rock varnish on a rock's surface to reveal the lighter rock underneath. Rock varnish is a thin layer of tiny clay particles which are deposited on rocks in desert environments. These clay particles are attached to rock surfaces by bacteria that lives there. Manganese in the clay gives rock varnish a dark color. In time, the color of the exposed interior becomes more like the color of the surface because of the rock varnish's regrowth.

There are several techniques for making petroglyphs. Striking one rock with another is called direct percussion. Indirect percussion refers to pecking the surface of one rock by holding a second rock as if it were a chisel and striking that with a third rock. A third technique, resulting in various line depths, is to scrape at the surface of the rock.

Pictographs are designs made by painting on rocks or in caves. Colorful plants and minerals were ground up and mixed with protein based liquids such as egg, blood, or urine to make different colors of paint. The pigments were applied using sticks, brushes, fingers or hands.

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