Chaco Culture National Historical Park

Who Built Chaco Canyon's Great Houses?

New archaeological evidence shows that human migrations across the Bering Straits may have begun as early as 38,000 BCE, but certainly no later than 11,000 years ago. At the end of the Pleistocene Age these Paleo Indians followed herds of mammoths and long-horned bison southward along an ice-free corridor in western Canada.

Between about 9500 and 9000 BCE, an increase in moisture nourished the spread of now extinct prehistoric mammals such as the mammoth, bison, horse, camel and sloth. Following these food sources, Paleo Indians arrived in the Southwest, wandering from campsite to campsite, stopping at kill sites to slaughter and process the large animals they hunted. Early sites contain the fluted Clovis points used to hunt mammoths. Folsom points are found at later sites because the Folsom hunters' chief source of food was the bison which required different weapons. To date, no Paleo-Indian sites have been discovered on the Chaco Plateau, although evidence of Folsom hunters has been found.

Anthropologists don't believe that these Paleo Indians were the direct ancestors of the peoples who settled northwestern New Mexico. They are thought to have continued on east, while new groups filled the gaps left behind. This event begins a significant period in the prehistory of the American Indians called The Archaic Stage. The Archaic Stage extends from about 8000 to 500 BCE. During this time the lifestyle of the people was dependent on a broad range of food processed with unelaborated tools. In northwestern New Mexico this lifestyle emerged about 5500 BCE, later than in other parts of the Southwest, and this variation of the food collecting pattern is termed The Desert Culture.

Campsites of these new wanderers were similar to those of the Paleo Indians; they are marked by hearths and fire cracked rocks as well as by the presence of stone tools for daily tasks including those for killing and processing small game, and for grinding and crushing plant foods. Some time between 3400 and 1000 BCE a variety of small ear corn native to Mexico was introduced to the Southwest. At first it had little impact on the diet of these early Anasazi, but between 1000 BCE and 1CE nomadism began to give way to a more sedentary lifestyle based in the cultivation of corn and squash. As the domestication of emmer wheat and six-rowed barley led to the rise of great sedentary civilizations in the Near East, so corn contributed to the development of what is called Anasazi culture.

Early Anasazi culture is termed the Basket Maker II period, a time when major storage containers were still woven baskets. People began living in a type of house made by embedding short logs horizontally in mud plaster covered with a flat pole and adobe roof. One Basket Maker II site has been identified in Chaco Canyon.

Between 150 and 700 CE what archaeologists define as Chaco culture began. Many small settlements of pit houses were built around the Chaco Plateau, each settlement probably a group of related families.

What is a pit house and what does it have to do with the great houses? In his article "The Mesa Verde Region: Chaco's Northern Neighbor," William D. Lipe defines a pit house as a semi-subterranean structure of wood, stone and mud, a "protokiva" used for cooking, sleeping and rituals, with a small cluster of adjacent surface rooms for storage and perhaps extra living space.

At first it was believed that the pit house was the forerunner of the great house and the great kivas, but tree ring dating has shown that at the height of Chaco culture, pit houses and great houses existed side by side.

During the Basket Maker III period some of the larger pit house settlements had sacred chambers built like large pit houses-protokivas. In the Chaco Plateau area, the need for irrigating crops led to the exploitation of water held in natural tanks on the canyon rims. Water for home use was collected at natural seeps and springs and carried home in clay pots. During this period most crops were planted along the edges of dry washes or similar areas and watered by natural precipitation.

The bow and arrow replaced the atlatl and spear as primary hunting weapons, the first true Anasazi pottery emerged, usually either crude gray pots for cooking or pots painted white and black using basket designs made for other purposes. Evidence of increased trade is shown by the present of some pottery coming from the south and north. Dogs were domesticated during this time; a sipapu appeared in pit house floors and utensils were placed in graves, indicating a belief in the supernatural, a religion.

Between about 700 and 850 CE (Pueblo I period) a major change in architecture occurred. Jacal type buildings were constructed on the surface; pit structures were smaller and appear to have been used largely for religious purposes. Jacal is a small structure having walls made of rows of thin, vertical poles filled in and plastered with mud. By 800 CE small multi-room houses or villages with walls of posts, adobe and a few stones were being constructed on shallow foundations lined with stone slabs. Also during this period, arc shaped groups of storage rooms with housing in front came into use. Archaeologists note the gradual elimination of timber from wall construction and its replacement with rocks cemented in a mud mortar.

About 850 CE Pueblo I gave way to the Early Pueblo II period when groups of small pueblos grew up around patches of farming land. Now the population began to concentrate in a smaller number of communities. Fewer crescent shaped villages were built, more rectangular or linear villages built of elementary coursed masonry set in mud appeared. These villages had kivas near the front and the features of these kivas were more or less standardized.

Early Pueblo II kivas are partially lined with masonry and include a bench going all the way round the perimeter wall, a ventilator, a slab deflector between the ventilator and the fire pit and sipapu, a cribbed log roof supported by four or more posts, with a smoke hole in the center of the building.

It is believed that during this period the Chaco Plateau may have reached its carrying capacity insofar as population was concerned, and that during times of drought or food shortage food sources outside the plateau had to be found.

In most other Anasazi areas, the high point of Anasazi civilization was reached about 1020 CE, but in Chaco Canyon this point arrived 50 years or so earlier. This Late Pueblo II phase (which due to various naming systems is also known as the Early Bonito phase and the Hosta Butte phase) is the beginning of what the late Cynthia Irwin Williams, who excavated the Salmon great house ruins, called the "Chaco Phenomenon." In his preface to In Search of Chaco, New Approaches to an Archaeological Enigma, editor David Grant Noble asks, popular appeal aside, why this phrase, the Chaco Phenomenon, was so quickly adopted. And answers, because of the skilled craftsmanship and the monumental scale of the buildings in the central portion of Chaco Canyon, with their linear roads and "built" landscape that make "Downtown Chaco" seem urban compared to the surrounding areas. This unique construction was to set the Chaco Anasazi apart from the others.

There is speculation that population pressure and putting more land under irrigation for agricultural purposes, plus the resulting need for more food storage units, may have caused the beginning of what we see today in Chaco Canyon. In any case, between 920 and 1020 CE construction of six major great houses began (Pueblo Bonito, Chetro Ketl, Una Vida, Peñasco Blanco, Hungo Pavi, Kin Bineola) along with work on more small villages housing just a few families. Early masons used irregular sandstone slabs laid horizontally so that their inner edges almost interlocked, cemented by copious adobe mortar. For example, at Pueblo Bonito this construction took the form of some 25 one-story houses built in a crescent-shaped group.

The great kiva, reintroduced from the Basketmaker II Period, is found set apart from the pueblos but central to them. Archaeologists note variations in style of clothing, utensils and footwear, but they believe one of the most important developments in this period was the complexity of many aspects of Chaco society which began to function as a cohesive economic system.

Between approximately 1020 and 1120 CE the Chacoans reached a level of excellence in architecture and in many other arts far beyond their peers. An estimated 5000 to 6000 people lived in about 400 settlements scattered in the vicinity of Chaco Canyon. In this century 10 more great houses were built while the six earlier great houses saw extensive building. The new great houses include Casa Chiquita, Kin Kletso, Kin Klizhin, Kin 'Ya'a, New Alto, Pueblo Alto, Pueblo del Arroyo, Pueblo Pintado, Tsin Kletzin and Wijiji.

One of Chaco's fascinating anomalies appears during this same time period. Side by side with the core and veneer construction seen in many of the great houses are many small villages--seldom larger than 25 rooms--built in the older, uncored style sometimes called the Hosta Butte style. And, of the 16 great houses built between 920 and 1120 CE, 12 show the Classic Bonito construction, but four others were built in the McElmo style (examples: Kin Kletso and Pueblo del Arroyo). It is believed that different groups of Anasazis built these structures and apparently lived side by side in relative harmony.

Tree ring dating has shown that most of the building took place during this Early Pueblo III phase and that construction was on a magnificent scale. Great houses or towns of four and even five stories sprang up around open plazas. Kivas were built both in the plazas and enclosed within room blocks. The tower kivas, whose purpose is still debated, appear in some of the great houses.

To meet the needs of a growing population, the water system was expanded and more of the canyon bottom put under irrigation. Nevertheless, the canyon couldn't feed itself and food and many everyday utensils were imported. In his "Artifacts in Chaco: Where They Came From and What They Mean," H. Wolcott Toll used chemical analysis to determine the source of much Chaco Canyon pottery. Gray ware for everyday cooking came from the eastern slopes of the Chuska Mountains, some 40 miles to the west. Fine black on white pottery was imported from Red Mesa Valley south of Chaco Canyon, from northeastern Arizona and north of the San Juan River, as well as from the eastern Chuska area. A smaller amount of red and brown ware pottery was brought from Mogollan areas of east-central Arizona and western New Mexico, or from southeastern Utah. He noted that a quantity of hard rock for edged tools was also imported.

After reading the above, it's no surprise to learn that trees used in building the Chaco great houses came from the Chuska Mountains and the Mt. Taylor area, both about 40 miles distant.

All of which demonstrates that whatever form it took, Chaco society during the Classic Bonito phase was complex with far flung associations and interrelationships.

In the 100 years after 1120 (called the Late Pueblo III Phase) little new construction was undertaken. New great houses along the San Juan River-Salmon and Aztec-saw population growth and building as Chacoan people began to migrate away from the Chaco Plateau. There is speculation as to the reasons for this decline; the cause most often cited is a severe drought between 1130 and 1190 which made the Chaco Canyon area uninhabitable. Other theories include lowering of the water table due to extensive deforestation and over farming resulting in a build up of alkali in the soil. In any case, what anthropologists call Chaco Culture came to an end and the peoples living in and around Chaco Canyon began to leave. Some went west and settled the Hopi mesas; some went south to Mt. Taylor and beyond, establishing the pueblos of Zuni, Laguna and Acoma; some turned east, establishing the pueblos between the Rio Puerco and the Rio Grande and some went as far as northern Mexico where they settled in the former Toltec trading community of Cases Grandes (Paquimé).

For several centuries after this, there were brief reoccupations by wanderers from north of the San Juan River, but the Chaco Phenomenon was over.

Copyright 2005 by Lynne D. Escue "Reproduction without permission prohibited."