New Mexico: Aztec Ruins Summary

  • Last updated on November 10, 2022

This monument, on twenty-seven acres, is devoted to Anasazi pueblo ruins dating from the twelfth through thirteenth centuries; it includes six major archaeological sites, partially excavated, and the only fully reconstructed Anasazi kiva (ceremonial chamber).

Site Office

Aztec Ruins National Monument

P.O. Box 640

84 County Road 2900

Aztec, NM 87410-0640

ph.: (505) 334-6174

Fax: (505) 334-0640

Web site:


One of the best-selling books of the 1840’s in the United States was The Conquest of Mexico by William Prescott. The American imagination was fired by Prescott’s account of central Mexico’s magnificent Aztec Empire and its destruction by the Spanish. When American scouts came upon a number of ruins in the United States’ southwestern territory during that period, ruins of great age that indicated the existence of some impressive civilization, these European Americans preferred to believe them the work of the Aztecs, rather than of the ancestors of the local Indian tribes. One of these sites, in northwestern New Mexico, was thus named Aztec Ruins. Thirty years later settlers arrived in the area and founded a town they called Aztec, after the ruins.

Anasazi Civilization

Throughout the Four Corners area of the American Southwest, in the land drained by the San Juan River, a great civilization did in fact exist and reached its height there in the twelfth century, disappearing by the end of the thirteenth century. This civilization, known today by the Navajo name Anasazi (“ancient ones”), developed the style of dwelling house now called pueblo (Spanish for “village”). They built breathtaking cliff dwellings in such places as Mesa Verde, Colorado, and Canyon de Chelly, Arizona, and expansive structures in river basins sites such as Chaco Canyon, New Mexico. These were the builders of the impressive ruins on the bank of the Animas River, centuries before the Aztec Empire arose and farther north than the Aztec civilization ever spread.

Early Exploration of the Ruins

To the first white settlers of Aztec, the ruins were a curiosity, an impediment to agriculture, and a convenient source of building supplies. The ruins appeared as large mounds of building debris covered with the accumulated sand and dirt of centuries, overgrown with vegetation. They briefly drew the attention of anthropologist Lewis H. Morgan in 1878; he surmised a relationship with the ruins of Chaco Canyon. Then in 1881, a local schoolmaster took a group of his students on a exploration of the ruins. They broke through the crumbling masonry walls and found themselves in a mazelike series of long-buried rooms. To their surprise they found skeletons along with pottery artifacts. The interest of the community was aroused, and soon the ruins were a frequent target for artifact-hunters and vandals. Finally in 1889 the property was purchased by John R. Koontz, who kept the vandals out. A few years later Warren K. Moorehead was allowed to survey but not dig the ruins. At the same time archaeologists were beginning to excavate other Anasazi ruins in the region and seek information about their culture.

In 1916 the new owner of the site, H. D. Abrams, agreed to allow an excavation. To direct the project which lasted from 1916 to 1921, the American Museum of Natural History selected Earl H. Morris. Morris was a native of the region, educated at the University of Colorado, and familiar with various Anasazi sites. Because of the proximity of the town of Aztec, he had a ready supply of laborers, townspeople who both needed the money he offered and took a personal interest in what was happening to “their” ruins.

Morris decided to work on the large western mound, dubbed the West Ruin. Clearing of the ruin was the first and one of the most arduous tasks. Once the vegetation was gone, the impressive size of the ruin was apparent. It spanned some 360 by 280 feet in a roughly rectangular structure, built around a central courtyard 180 by 200 feet. As the excavation progressed, a complex of 353 rooms was revealed. The pueblo contained 221 interconnected rooms on the ground level, 119 rooms on a second story, and 12 rooms on a third. There were 29 small kivas, probably for individual clan use, and, in the courtyard, a Great Kiva for the use of the community.

Construction of the Ruins

The pueblo’s design indicates an awareness of the importance of solar orientation; the highest wing of the pueblo was on the north, with only minimal ventilation openings in the wall. The lowest part of the structure faced south, to permit the winter sun to warm all of the building. The north wing had five and sometimes six rows of rooms from its south wall to its north. The east wing was five rooms deep; the still-uncleared west wing, seven rooms deep. The south wing, a single-story bowed structure, was one room deep.

The construction was very similar to that found at Chaco Canyon sites, although the stonework was not as fine because the local sandstone did not break as cleanly. The walls were filled with a rubble core, then faced with shaped blocks of sandstone set in alternating courses of thick and thin stones. In some places the rows included alternating colors as well, the final effect clearly intended to be aesthetically pleasing. The veneer blocks were not bonded to the core, causing an intrinsic weakness in the structure. Finally the sandstone surface was thickly covered with mud plaster. The Anasazi accomplished this impressive construction without metal technology, without wheeled transportation, and without draft animals.

Early Occupation Periods

The evidence that Morris and his team uncovered in the West Ruin at Aztec, in the form of varying construction styles, pottery styles, and similarities to other sites, made clear one significant fact in the history of the site: It was occupied twice, by two culturally different groups of Anasazi, separated by a period of perhaps fifty years. The striking similarity in building techniques to those at Chaco Canyon convinced Morris that the builders of the West Ruin were somehow related to the Chacoans. Recent aerial archaeological surveys have revealed the existence of an extensive network of roadways radiating out from Chaco Canyon. Aztec may have served as a satellite community, providing both living space and surplus food to the highly populated Chaco center. Tree-ring dating of beam samples from the pueblo indicated that the original beams were cut between 1111 and 1115, with a few more dating to 1124. This dates the West Ruin to a period only forty years after the construction of Pueblo Bonito at Chaco Canyon. Evidence of migration from Chaco Canyon suggests that the Chacoans left Aztec Ruins only about fifty years after its construction.

The presence of Mesa Verde-style pottery, intramural burials, and construction techniques in refurbished areas of the pueblo indicates a later occupation by people from the north. Tree-ring dating of remodeling beams indicates that they were cut between 1220 and 1260, with most cut between 1225 and 1252.

The Disappearance of the Anasazi

The evidence from Aztec Ruins suggests that the disappearance of the Anasazi from the entire Four Corners area by the end of the thirteenth century was not due to a single mass exodus but rather occurred in several waves of migration. Tree-rings have revealed that a long and serious drought affected the whole Colorado Plateau from 1130 to 1190, a disaster for an agricultural people like the Anasazi. The Chacoans, although possessing a large and complex culture based at Chaco Canyon, apparently moved further south at an early date, by the late twelfth century, and the people at Aztec went with them.

The Mesa Verdians left their cliff-top fields and cliff dwellings and moved south but paused in the abandoned pueblo they found on the bank of the Animas River. The river may have permitted them to continue their agricultural efforts longer. There they modified the building and the kiva to suit their own taste, and added new buildings as well. It was probably they who built the East Ruin, still unexcavated. Another drought, which lasted from 1276 to 1299, may have precipitated their departure from the region. They stayed until the end of the thirteenth century, when they too moved farther south, to the Santa Fe River, where the descendants of the Anasazi, the Pueblo Indians, live today.

Anasazi Building Methods

It is not known how the Anasazi were able to build their multistory walls when they had no technological means of raising building materials. Most probably it was a matter of human labor hauling stones and baskets of mortar up ladders in the interior, with masons working from temporary platforms, debris piles, or nearby roofs. It is possible that there may have been exterior balconies as well, since there is some inconclusive evidence for one on the north wall.

The walls of the interior rooms were also plastered; some of this material still remains. Usually the rooms were covered with an uncolored clay tempered with sand. In some rooms there was a red-tinted wainscoting against gypsum-white upper walls; there also were some rooms with incised or painted patterns for decoration. In one room white hand prints decorate the ceiling beams.

The excavators found nineteen of the original room ceilings in the West Ruin intact. The ceilings were elaborate constructions, supported by large pine or juniper beams that spanned the rooms. Over these beams poles of pine, juniper, or cottonwood were closely laid perpendicular to the beams. These were sometimes topped by a willow matting laced with yucca, perhaps partly decorative, perhaps to protect the occupants from falling dust. The final layer was of juniper splints covered with a thick deposit of tamped earth; this would form either an exterior roof or the floor of an upper room.

There were no windows as such in the pueblo. Ventilation was provided by small openings in the outer walls, or by ventilation shafts to those openings. Rooms in the deep interior that lacked fresh air apparently were used primarily for storage, with the exterior, better-ventilated rooms used for habitation. Ladders were used for access to one floor from another; door openings were placed a foot above floor level to protect floor-level hearths from drafts. A few doorways were built in room corners; the feat required considerable engineering skill.

A number of rooms had been abandoned to other uses and became trash dumps. In some, human remains were found as well, at times buried in the floor in shallow graves, at other times simply placed on the floor. Burial within abandoned rooms was typical of the late period of culture at Mesa Verde; this evidence would become important to Morris’s interpretation of the Ruins.

Rich Diversity of Artifacts

A rich diversity of stone and bone tools, shell beads, and jewelry was found within the West Ruin, along with several hundred intact pieces of pottery. Some were utilitarian pots, intended for cooking; some were decorated. Perishable artifacts such as wooden arrow shafts and bows, snowshoe frames, cradleboards, ladders, various types of basketry, moccasins, yucca sandals, and reed-stemmed cigarettes were also found, telling archaeologists much about the character of life in the pueblo.

In 1921, as the end of the dig grew near, Morris determined to excavate a great depression in the courtyard, which he believed to be a kiva, a subterranean ceremonial chamber. Excavation proved him correct. This kiva was much larger than those the excavators had found within the pueblo; it was forty-one feet in diameter. Great Kivas were known from the Chaco Canyon area, but this one held a surprise. Around its rim at ground level were fourteen arc-shaped chambers, each with an exterior doorway, each connected to the kiva proper by vertical wall slots with embedded rungs. Like most other kivas, the Aztec Great Kiva is laid out on a north-south axis. The central surface room on the north is larger than the other thirteen, with special features, including what seems to be an altar, and a stairway to the kiva chamber.

On the kiva floor Morris found the remains of four massive masonry pillars, each three feet square, footed on four stacked slabs of limestone lying at the bottom of a hole, the limestone in turn bedded on a lignite foundation. Clearly these pillars were intended to support a great weight. Because there were no pilasters around the circular wall, but only two benches, Morris deduced that the Great Kiva had been covered by a giant circular flat roof rising ten to twelve feet above the level of the courtyard. He decided that a central square of beams resting on the four pillars had supported at least twenty-three beams radiating like spokes from the center to the exterior walls. Over these the Anasazi would have lashed layers of saplings and juniper splints and covered them with a thick layer of earth. When completed, the roof would have weighed about ninety tons, all supported without the use of securing nails, tenons, or pegs.

Morris was unable to complete his excavation of the West Ruin before his funds ran out and the museum called a halt. About a quarter of the ruin was left covered.

Modern Preservation Efforts

On January 24, 1923, Aztec Ruins was declared a National Monument by presidential proclamation. Most of the land was donated by the American Museum of Natural History, and some was purchased from the heirs of H. D. Abrams and from other property owners. Consisting of 27.1 acres, the site is now administered by the National Park Service.

Because the removal of covering debris invariably exposes a site to decay, the American Museum of Natural History had provided funding for the preservation and stabilization of the ruins as they were excavated; this was a very innovative approach for the time. Walls were supported and capped in cement, intact ceilings were covered with roofs, and extensive drainage systems were set up. Repairs and stabilization were, and are, a continuous problem. The Great Kiva was particularly subject to erosion and decay, and concerned local citizens persuaded the federal government to act. It was decided not merely to repair but to reconstruct the Great Kiva. Earl H. Morris returned to supervise the work, which began in 1933. It was the ultimate test of his theory of roof construction. The Great Kiva at Aztec Ruins is still the only building of its kind ever restored.

Exploratory work was done on the East Ruin in 1957. It seemed to be in a state of preservation similar to that of the West Ruin; workers found thirteen intact ceilings on the west edge of the mound. The building style suggests that this pueblo was built by the Mesa Verdians at the same time that they were remodeling the West Ruin pueblo.

In 1953 park archaeologists excavated the Hubbard Mound, a site northwest of the West Ruin. They found three increasingly substantial layers of construction, all from the Mesa Verdian period. The third and final layer proved the most interesting. Three concentric masonry walls rose some twelve feet around a central space sixty-four feet in diameter. Spaces between the walls had been divided into twenty-two small chambers, into which there were no doorways. Entrance must have been through ceiling hatchways. In the center of the circular courtyard was a kiva three feet below the ground. None of the walled chambers connected to it. A similar circular structure was found located to the east of West Ruin. The ceremonial nature of these structures seems apparent, but their exact use remains a mystery.

Today the visitor to Aztec Ruins can tour some of the rooms in the West Ruin, enter the Great Kiva restored to its original appearance, and view the Hubbard Mound. Other mounds on the site remain unexcavated.

For Further Information
  • Corbett, John M. Aztec Ruins National Monument, New Mexico. Washington, D.C.: National Park Service, 1963. A straightforward account of the park and its history.
  • Lister, H., and Florence C. Lister. Aztec Ruins on the Animas: Excavated, Preserved, and Interpreted. Albuquerque: University of New Mexico Press, 1987. Provides a thorough description of the excavation of Aztec Ruins by Morris and others and includes many photographs of the work in progress.
  • Thybony, Scott. Aztec Ruins National Monument. Tucson, Ariz.: Southwest Parks and Monuments Association, 1992. A brief history of the park and of the Pueblo Indians.
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