Funding from the National Science Foundation will support archaeological field research in Chaco Canyon, New Mexico, directed by Drs. W. H. Wills and Patricia L. Crown of the University of New Mexico. This project is designed to investigate the role of water management during the beginning of a period of rapid social change that occurred in the semi-arid Colorado Plateau of the American Southwest just over one thousand years ago. Known to archaeologists as the "Bonito phase" (ca. A.D. 850 - 1140), this transformation is marked by the appearance of large masonry buildings called Great Houses in the midst of dispersed farming communities comprised of small household settlements. Some Great Houses were multistoried structures with more than 500 individual rooms, and some were built outside Chaco, but the largest, best-known and most iconic is Pueblo Bonito in Chaco Canyon. Pueblo Bonito is one of more than a dozen Great Houses located in the canyon, which is in turn the physical center of a very high density of archaeological sites and features within the larger San Juan Basin of northwestern New Mexico. Researchers have proposed that Chaco was the cultural center of an extensive social network that stretched from the Grand Canyon to the Rio Grande, and from the southern Rocky Mountains to the highlands of southern New Mexico. In the historical development of indigenous southwestern societies, Chaco is thought to have been a major turning point that established fundamental cultural patterns still evident among the Pueblo peoples of New Mexico and Arizona.
However, despite more than 100 years of archaeological research in and around Chaco Canyon, archaeologists and other researchers have made little progress reaching agreement on the likely factors responsible for the shift from family-based economies to corporate systems involving communal dwellings and massive amounts of labor invested in architecture. The lack of consensus seems to stem, in part, from a paucity of information about local environmental and cultural conditions during the earliest phase of Great House development. Great Houses were designed and built over periods of several human generations, and these large structures typically grew on top of earlier settlements, eventually destroying the oldest occupations or burying remnants under the massive walls. The research program supported by NSF will attempt to improve our understanding of this important period of change by examining deeply buried cultural deposits and features beneath Pueblo Bonito. Access to these portions of the site will be obtained by reopening deep trenches originally excavated by the National Geographic Society in the 1920s and reexamining the cross-sections with new analytical methods. The original excavations sought only to define relationships between certain types of pottery found in the deposits and ignored almost every other sort of data. The new work will bring together a team of geologists, biologists and archaeologists to determine whether artificially constructed adobe features noted in the 1920s (but largely ignored) are the remains of an irrigation system. If these features are canals, then we would presume that water control was a critical element in the rise of Great House communities.
The broader impacts of this study include the better appreciation of the socioeconomic processes that characterize the transition from small-scale social networks to dense, hierarchical societies based on agriculture, and a greater understanding of the sustainability of irrigation economies in arid environments. Graduate students participating in this research will gain important training in field methods and new theoretical applications in archaeology. The project is especially committed to training Native American students in anthropology and allied fields and these students will be part of the emerging generation of Native American scholars working on ancestral archaeology in the American Southwest.
