About 3.3 million years ago, a fissure near Pilar vented molten lava which flowed about 25 miles south on top of the river-cobble and sand which forms the Santa Fe Group, a sedimentary deposition comprising eroded material from the Sangre de Cristo Mountains. When the hot lava cooled, it formed a hard canoe-shaped basalt layer. As the Rio Grande began to flow about 440,000 years ago, it eroded the softer landscape around the basalt layer, eventually leaving the protected mesa cap towering one thousand feet above the river basin, as it is today.
Basalt boulders have a light brown color when newly formed or when continuously covered with soil. Erosional processes that expose the boulders to light, moisture and air cause a dark patina or desert varnish to develop on the surface of the boulders. New fractures, boulders becoming uncovered and the process of creating petroglyphs on the boulders breaks through the dark patina, exposing the natural lighter color below.
The terrain on Mesa Prieta is rugged and steep.
Deep fissures and rugged escarpments cover the side of the mesa.
Mesa Prieta, meaning ‘dark mesa’, is a thirty-six square mile mesa extending twelve miles in a northeasterly direction. Over 60,000 examples of rock images are estimated to exist on the mesa in addition to other archaeological features. The east side of the mesa is closely adjacent to the Rio Grande; the western side has large habitable and agricultural areas between the base of the mesa and the nearest drainage.
Archaeologists note that there are numerous other archaeological features such as shrines, water control systems, check dams, lithic scatters, ceramics, field houses and other structures, grid gardens and ancient and historic trails in addition to the rock images. The number and quality of the glyphs make the mesa similar in importance to other major sites in New Mexico such as Petroglyph National Monument in Albuquerque and the Three Rivers site near Tularosa. Approximately 80% of the glyphs and other features are on private land. Most of the remaining 20% are located on Bureau of Land Management land with The Archaeological Conservancy owning 156 acres and Ohkay Owingeh a small amount.
Prehistoric agricultural check dam; agricultural features constructed of rocks are common on the mesa; recording volunteers record these structures as Cultural Landscape features.
While the mesa's more remote location has spared it the problems of Petroglyph National Monument, there are troubling issues. Development is encroaching in some areas. Some important petroglyph sites have been mined for riprap. Mining continues today and the threat of future mining is always present. Vandalism has been less extensive than at some sites, but is evident in the most visited sections. One of the worst hazards is destruction caused by off road vehicle traffic in areas with concentrations of glyphs, particularly on BLM land. Some areas of concentrated glyphs on steep slopes have been seriously eroded by centuries of overgrazing by sheep and torrential monsoon rains in the overgrazed areas. With increased visitation to the petroglyph areas, escalation of erosion has been observed, particularly in areas where visitors do not stay on established trails.
MESA PRIETA PETROGLYPH STYLES
The rock images found on Mesa Prieta represent three distinct time periods: Archaic, Pueblo IV and Historic including Modern. All three types are well represented which makes the site unique and testifies to intense human occupation in the surrounding areas over the past several thousand years. Folsom points have been found which confirm about ten thousand years of human activity in the area. The availability of water nearby has made Mesa Prieta a compelling locale for humans and its huge, dark boulders are ideal for rock graphics.
Archaic period images are scattered around the site. They have much in common with archaic glyphs found around the world. Though exact dates are not verifiable at this time, the images can be related to Archaic era glyphs found in the Glorieta area of New Mexico that were associated with wood samples that have been carbon dated to about 5,000 years ago. Archaic images of meandering lines, asterisk-like forms, one-pole ladders, grids and other abstract forms as well as human and animal hand and footprints are found on the mesa. Representational images of humans, animals, plants and other objects are not found among the Archaic glyphs.
Ancient Archaic Period Petroglyph. These petroglyphs are so heavily repatinated that they are often difficult to see.
These ancient images are deeply pecked into the basalt boulders and are so repatinated that visitors easily miss them. Many are barely discernible under the best light conditions. Hunter-gatherer people who were the first occupants of the area made Archaic images thousands of years ago.
Boulder showing cupules and a one poled ladder from the Archaic period. Cupules are archaeological features found worldwide and are thought to have ceremonial purposes.
The largest numbers of petroglyphs on the site are from the Pueblo IV period, roughly 1300 A.D. to 1600 A.D. Perhaps 75 % of the petroglyphs on Mesa Prieta fall into this category. These petroglyphs were created by Ancestral Puebloan peoples who filtered into the area around 1300 A. D., probably from the Four Corners region. They developed what has come to be known as the Rio Grande Style. The florescence of rock images reached its peak sometime before the arrival of the Spanish conquistador Juan de Oñate in 1598 who established a crown colony at Ohkay Owingeh (San Juan Pueblo).
A huge number and variety of glyphs were created during this period. These include circles, spirals, stars, geometric patterns, human and animal prints such as deer, elk, bear and turkey. Human figures appear as dancers, shamans, hunters, flute players, women giving birth and warriors. Most Pueblo IV glyphs are believed by archaeologists to be related to some form of ritual or ceremony.
This Ancestral Puebloan petroglyph shows several ceremonial figures including a shield bearer, a shamanistic figure with a two horned serpent across his body and a large headed figure with a headdress. A possible mountain lion or canine is at the top.
The mesa is well known for its large number of shields, shield bearers and flute players. It is one of the largest flute player sites in New Mexico and, wonderfully, has the largest number of animal flute players known. Recent research has identified numerous sun calendars and solar markers among the rock images.
The flute player is a common image in Ancestral Puebloan rock images. Animal flute players are unusual; the largest concentration of these images occurs on the Wells Petroglyph Preserve.
Snake images abound on the mesa. One of the most common types is the two-horned Awanyu. There are a few Awanyus in profile with one horn facing backward. Other snake images appear to have rattles on their tails or to have the appearance of lightning.
This image shows both one horned and two horned serpents emerging from a crack in the boulder. Serpents are thought to be mythological in Ancestral Puebloan images and are often associated with water and emergence into this world.
Animal images include deer, elk, dogs, a variety of birds, mountain lions, bears, bison, turtles, dragonflies and many that cannot be identified. The petroglyphs from the Pueblo IV period range from the crudely done and lightly pecked to others masterfully executed by Puebloans with great skill and a refined sense of line and form. Perhaps the largest category of glyphs during this period is that of “unidentified.” These are abstract forms that resemble nothing we recognize in the physical world.
The third major time period for petroglyphs on the mesa is that of the Historic era which began around 1600 A.D with the coming of the Spanish. The most common image is that of the Christian cross. Sheepherders and others created hundreds of examples. Less common but significant are the many images of horses and horses with riders.
This rider on a horse appears to be holding a spear. We know, by the subject matter, that this petroglyph was made after 1600 as the Puebloan people did not have horses prior to the arrival of the Spanish.
A unique feature on the mesa is that of Spanish lion images; several have been found and some are magnificently done. Other Historic images include wagons, inscriptions, dates, names, initials, churches and humans.
This unusual and exquisitely crafted lion appears to have a crown on its head. Note how the tail curves above its back in a proud stance. Several of these images occur on Wells Petroglyph Preserve and elsewhere on Mesa Prieta and it is conjectured that their design imitates Spanish heraldic depictions. Very similar lions are seen on artifacts and furniture in the collections of the Museum of New Mexico.