Chaco Canyon - Architectural Heart of the Ancestral Puebloan People

An Ancestral Puebloan Landscape

Overview of Pueblo Bonito, Chaco Canyon
Overview of Pueblo Bonito, Chaco Canyon. Chris M. Morris

Chaco Canyon is a famous archaeological area in the American Southwest. It is located in the region known as the Four Corners, where the states of Utah, Colorado, Arizona, and New Mexico meet. This region was historically occupied by Ancestral Puebloan people (better known as Anasazi), and is now part of the Chaco Culture National Historical Park. Some of the most famous sites of Chaco Canyon are: Pueblo Bonito, Peñasco Blanco, Pueblo del Arroyo, Pueblo Alto, Una Vida, and Chetro Kelt.

Because of its well-preserved masonry architecture, Chaco Canyon was well known by later Native Americans (Navajo groups have been living at Chaco since at least 1500s), Spanish accounts, Mexican officers and early American travelers.

Explorations and Archaeological Investigations of Chaco Canyon

Archaeological explorations at Chaco Canyon began at the end of the 19th century, when Richard Wetherill, a Colorado rancher, and George H. Pepper, an archaeology student from Harvard, began to dig at Pueblo Bonito. Since then, interest in the area has grown exponentially and several archaeological projects have surveyed and excavated small and large sites in the region. National organizations like the Smithsonian Institution, the American Museum of Natural History and the National Geographic Society have all sponsored excavations in the Chaco region.

Among many prominent southwestern archaeologists who have worked at Chaco are Neil Judd, Jim W.

Judge, Stephen Lekson, R. Gwinn Vivian, and Thomas Windes.


Chaco Canyon is a deep and dry canyon that runs in the San Juan Basin of northwestern New Mexico. Vegetation and wood resources are scarce. Water is scarce too, but after the rains, the Chaco river receives runoff water coming from the top of the surrounding cliffs.

This is clearly a difficult area for agricultural production. However, between AD 800 and 1200, ancestral puebloan groups, the Chacoans, managed to create a complex regional system of small villages and large centers, with irrigation systems and inter-connecting roads.

After AD 400, farming was well established in the Chaco region, especially after the cultivation of maize, beans and squash (the "three sisters") became integrated with wild resources. The ancient inhabitants of Chaco Canyon adopted and developed a sophisticated method of irrigation collecting and managing runoff water from the cliffs into dams, canals, and terraces. This practice--especially after AD 900--allowed for the expansion of small villages and the creation of larger architectural complexes called great house sites.

Small House and Great House Sites at Chaco Canyon

Archaeologists working at Chaco Canyon call these small villages "small house sites," and they call the large centers "great house sites." Small house sites usually have less than 20 rooms and were single-story. They lack big kivas and enclosed plazas are rare. There are hundreds of small sites in Chaco Canyon and they began to be constructed earlier than great sites.

Great House sites are large multi-storied constructions composed of adjoining ​rooms and enclosed plazas with one or more great kivas. The construction of the main great house sites like Pueblo Bonito, Peñasco Blanco, and Chetro Ketl occurred between AD 850 and 1150 (Pueblo periods II and III).

Chaco Canyon has numerous kivas, below-ground ceremonial structures still used by modern puebloan people today. Chaco Canyon's kivas are rounded, but in other Puebloan sites they can be squared. The better-known kivas (called Great Kivas, and associated with Great House sites) were constructed between AD 1000 and 1100, during the Classic Bonito phase.

Chaco Road System

Chaco Canyon is also famous for a system of roads connecting some of the great houses with some of the small sites as well as with areas beyond the canyon limits.

This network, called by the archaeologists the Chaco Road System seems to have had a functional as well as a religious purpose. The construction, maintenance and use of the Chaco road system was a way to integrate people living over a large territory and giving them a sense of community as well as facilitating communication and seasonal gathering.

Evidence from archaeology and dendrochronology (tree ring dating) indicates that a cycle of major droughts between 1130 and 1180 coincided with the decline of the Chacoan regional system. Lack of new construction, abandonment of some sites, and a sharp decrease in resources by AD 1200 prove that this system was no longer functioning as a central node. But the symbolism, architecture, and roads of the Chacoan culture continued for few more centuries becoming, eventually, only a memory of a great past for later puebloan societies.


Cordell, Linda 1997. Archaeology of the Southwest. Second Edition. Academic Press

Pauketat, Timothy R. and Diana Di Paolo Loren 2005. North American Archaeology. Blackwell Publishing

Vivian, R. Gwinn and Bruce Hilpert 2002. The Chaco Handbook, An Encyclopedic Guide. The University of Utah Press, Salt Lake City