Reading rock art without harming it

The canyon country holds two kinds of rock art. Pictographs are painted onto the stone, with pigments made from minerals such as red and yellow iron oxides, white clays and gypsum, and black from charcoal or manganese, bound with plant or animal material. Petroglyphs are pecked, ground or scratched through the dark skin of desert varnish on a cliff face to the paler rock beneath. Both are old. Some panels on Cedar Mesa are attributed to the Basketmaker people of roughly two thousand years ago; others were made by later Pueblo communities, and Navajo and Ute images record still later centuries.

They are not relics of a people who disappeared. The Hopi Tribe, Zuni and other Pueblo communities trace their ancestry to the people who lived in these canyons, and many of the images carry meaning in living traditions. Treating a panel as a picture to be improved is the first mistake, and every other one follows from it.

Why the panels last, and why that is fragile

Pictographs survive where little water reaches them: under overhangs, in alcoves, on walls that face away from the weather. Desert varnish, the coating of clay, manganese and iron that gives petroglyphs their contrast, forms over thousands of years. Both are thin. A painted figure may be a film of pigment a fraction of a millimeter deep, held to sandstone that sheds grains when rubbed.

That is why the gentlest-seeming habits do the most harm:

• Touching: skin leaves oils and salts that attract dust and lichen and hold moisture against the stone. One touch adds little; thousands of visitors touching the same figure wear it away.
• Chalking or outlining: chalk, charcoal or crayon traced along a faint line to make it photograph better fills the pores of the rock and confuses every later study of what was actually there.
• Wetting: splashing water to bring out a faded image dissolves salts, moves pigment and feeds the growth that slowly eats the surface.
• Tracing and rubbing: paper pressed against a panel, even with a soft pencil, abrades both pigment and varnish.
• Adding: initials, dates and new figures scratched beside old ones are vandalism. They also make later visitors more likely to add their own.

Photographs harm nothing, and a camera with good light and patience records more detail than chalk ever revealed.

What the law says

On federal public and tribal lands the Archaeological Resources Protection Act makes it a crime to excavate, remove, damage, alter or deface an archaeological resource without a permit, and rock art is covered. The penalties in the statute rise with the harm: up to a year in prison for a first offense, up to two years where the value and the cost of repair exceed $500, and up to five years for a repeat offense, with fines alongside. The act applies on public land whatever the status of the land around it, inside a national monument or outside one.

Utah law adds its own protection on state and school trust lands. Neither statute asks visitors to know the age of a panel.

Reading a panel well

Most of what can be learned from a panel comes from looking longer. Note what faces which way, which figures are painted over others, how high the images sit and what could be seen from where the maker stood. Visit at a time of day when low, raking sunlight brings out pecked lines, rather than trying to force them out with water or chalk. Then leave the panel exactly as found, including the ground beneath it.

Museum collections and published studies explain far more than a site visit can. The regional museums, the Natural History Museum of Utah among them, the state’s archaeology office and university research on Basketmaker and Pueblo imagery have done the slow work of describing and dating the art, and they are the place to start for anyone who wants to know what a figure might mean. Locations are deliberately left out of all of it, here included, because a panel known to fewer people tends to last longer.