Petroglyphs
Images pecked, carved or scratched into rock. Pictographs, by contrast, are painted onto it. In the American Southwest most petroglyphs were made by the ancestors of today’s Pueblo peoples and other tribes, who regard them as part of their living heritage; at Petroglyph National Monument in New Mexico there are more than 20,000.
Meaning
The U.S. National Park Service defines petroglyphs as images and designs made by engraving, carving or scratching away the dark layer of rock varnish on a rock’s surface to reveal the lighter rock beneath; they can be pecked, carved, incised, scratched or abraded, usually with a stone used as a hammer, sometimes with a second as a chisel. Rock varnish, or desert varnish, is a thin dark coat of clay held to the rock by bacteria and coloured by manganese and iron. Once a petroglyph is cut, the varnish slowly grows back, and how far it has darkened again gives a rough idea of age. At Petroglyph National Monument, on a volcanic ridge west of Albuquerque, the Park Service attributes most of the images to Ancestral Pueblo peoples, the ancestors of the people of the 19 Pueblos of New Mexico and of the Hopi in Arizona; others may be the work of ancestors of the Navajo and Apache, and some were made by Spanish settlers. More than 20 pueblos and tribes are culturally affiliated with the monument. The Park Service avoids the term “rock art” there, because the images are more than art and Native American languages generally have no words that describe things in artistic terms. The tribes consider the images and the land a sacred space, and touching them is forbidden.
Origin and history
The ridge began about 130,000 years ago, when lava poured from a crack in the earth west of what is now Albuquerque and cooled into dark basalt. The Park Service believes most of the petroglyphs were made by Ancestral Pueblo peoples between AD 1300 and the late 1600s, as their population grew and new villages were founded along the Rio Grande; a few may be 2,000 to 3,000 years old. Subject matter helps date them. The bow and arrow came into use in the Southwest about AD 500, so a panel showing it is later than that, and a horse or a horse and rider must be later than the Spanish arrival in 1540. Spanish settlers, who moved into the area from about 1600 and farmed the Atrisco land grant after the Pueblo Revolt of 1680, carved their own petroglyphs: mostly Christian crosses, copies of livestock brands and initials.
How many there are depends on the date of the count. The Park Service’s definitions page estimates nearly 20,000; an inventory begun in 1997 had recorded over 21,000 by May 2002 and expected close to 25,000; other Park Service pages say some 24,000. To many Native people, the Park Service writes, the petroglyphs are immeasurably old, an inseparable part of the landscape created at the beginning of time.
What is the difference between a petroglyph and a pictograph?
A petroglyph is cut into the rock; a pictograph is painted on it. The National Park Service describes pictographs as made with ground-up plants and minerals mixed into liquids such as egg, blood or urine, applied with sticks, brushes, fingers, hands or stencils, or even blown from the mouth. At Petroglyph National Monument fewer than one image in a thousand is a pictograph. The stencilled hands of the Cueva de las Manos in Patagonia, which UNESCO calls pictographs, are painted images of this kind. “Rock art” covers both, though the Park Service avoids the term at the monument.
What do the petroglyphs mean?
Their meanings belong to the peoples whose ancestors made them, and the Park Service does not try to give them. “We usually do not try and interpret the images or assign specific meanings,” it writes: some meanings were not meant to be known today, some not by the uninitiated, and the deepest are closely guarded by today’s Native peoples. Some petroglyphs record events for a family or a tribe; others have personal, private meanings; and a petroglyph’s orientation to other images, the landscape or the horizon matters as much as the image itself. The Park Service adds that some researchers think particular petroglyphs may tell a story, mark a trail or commemorate an event.
Footprints of the ancestors
For the Hopi, petroglyphs are among itaakuku, “our footprints”. Leigh J. Kuwanwisiwma, director of the Hopi Tribe’s Cultural Preservation Office, explains that when the Hopi emerged into the present world they made a covenant with the deity Maasaw to migrate until they reached the Hopi Mesas, and were instructed to leave footprints along the way: the ruins of villages, pottery, stone tools and petroglyphs, left as offerings and as proof of their migration and stewardship of the land. Petroglyphs mark land occupied by particular clans. At Tutuveni, “writing on rocks”, a shrine on the Salt Pilgrimage trail to the Grand Canyon, the carving of clan symbols is well documented, and the Hopi interpret clan symbols, handprints and ritual figures as signs made deliberately to connect descendants with their ancestors.
Petroglyphs elsewhere in the national parks
Other Park Service sites show other uses. At Puerco Pueblo in Petrified Forest National Park, sunlight falling through a crack between boulders crosses a small ringed petroglyph for about two weeks around the summer solstice, and the way the sun strikes spiral petroglyphs at Hovenweep National Monument shows that they were solar calendars. In what is now Virgin Islands National Park, the Taíno carved petroglyphs beside pools of water and in or near caves, places where, the Park Service writes, they communicated with ancestors who assembled there. Defacing such sites is illegal, and the Park Service calls it disrespectful to the peoples descended from the makers, whose ancestral heritage the markings are.
Read next
- Next in Cave and rock artLascaux cave paintingsHundreds of painted and engraved animals, horses above all, on the walls of Lascaux, a cave above Montignac in the Dordogne, France. They were made more than 20,000 years ago and found by four teenagers in 1940. The cave has been closed to the public since 1963.
- Spiral petroglyphs at Hovenweep were solar calendars, the NPS saysSpiralA line that winds outward from a centre. It is among the oldest carved signs: spirals cover the entrance stone of Newgrange in Ireland, built about 3200 BC, ancestral Pueblo people in the American Southwest carved spirals that sunlight marks at the solstices, and in Māori art the koru spiral is a symbol of creation.
See also
Cueva de las Manos (hand stencils), Caguana petroglyphs, Chauvet Cave, Altamira Cave, Cave art signs, Venus of Willendorf.
Sources
- Definitions (Petroglyph National Monument), National Park Service, Petroglyph National Monument, “Definitions”, U.S. National Park Service, Plan your visit › Definitions
- New Mexico: Petroglyph National Monument (National Park Service), National Park Service, “New Mexico: Petroglyph National Monument” (travel itinerary article), U.S. National Park Service, article
- Learn to look at petroglyphs and pictographs (National Park Service), National Park Service, “Learn to Look at Petroglyphs and Pictographs”, U.S. National Park Service, article
- Ang Kuktota (Leigh J. Kuwanwisiwma, Expedition), Leigh J. Kuwanwisiwma, “Ang Kuktota”, Expedition 46, no. 2 (2004), Penn Museum, Penn Museum (University of Pennsylvania Museum of Archaeology and Anthropology), article and glossary
- Cueva de las Manos, Río Pinturas (UNESCO), UNESCO World Heritage List, property 936, “Cueva de las Manos, Río Pinturas”, UNESCO World Heritage Centre, Description
- Leigh Kuwanwisiwma receives Public Archaeology Award (Hopi Tutuveni), Louella Nahsonhoya, “Leigh Kuwanwisiwma, Director of Hopi Tribe Cultural Preservation Office receives Governor’s Archaeology Advisory Commission ‘Public Archaeology Award’”, Hopi Tutuveni, June 2013, The Hopi Tribe (Hopi Tutuveni), article
The same shape elsewhere
Browse symbols formed from curves and waves or lines.
Researched, edited and approved by Rory Hansen before publishing. Last reviewed October 8, 2026. How we research
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