Migration was a key social process contributing to the creation of the ‘Chaco World’ between AD 800 and 1200. Dynamic social network analysis allows for evaluation of several migration scenarios, and demonstrates that Chaco’s earliest ninth-century networks show interaction with areas to the west and south, rather than migration to the Canyon from the Northern San Juan. By the late eleventh century, Chaco Canyon was tied strongly to the Middle and Northern San Juan, while a twelfth-century retraction of networks separated the Northern and Southern San Juan areas prior to regional depopulation. Understanding Chaco migration is important for comprehending both its uniqueness in U.S. Southwest archaeology and for comparison with other case studies worldwide.

Phenomenological archaeologists and GIS scholars have turned much attention to visibility—who can see whom, and what can be seen—across ancient landscapes. Visible connections can be relatively easy to identify, but they present challenges to interpretation. Ancient peoples created intervisible connections among sites for purposes that included surveillance, defense, symbolism, shared identity, and communication. In the American Southwest, many high places are intervisible by virtue of the elevated topography and the open skies. The Chaco phenomenon, centered in northwestern New Mexico between A.D. 850 and 1140, presents an ideal situation for visibility research. In this study, we use GIS-generated viewsheds and viewnets to investigate intervisible connections among great houses, shrines, and related features across the Chacoan landscape. We demonstrate that a Chacoan shrine network, likely established during the mid-eleventh century, facilitated intervisibility between outlier communities and Chaco Canyon. It is most likely that the Chacoans created this network to enable meaningful connections for communication and identity. We conclude that the boundaries of the Chaco phenomenon are defined in some sense by intervisibility.

We report measurements made on eight corncobs (Zea mays) excavated in the 1890s from Pueblo Bonito, Chaco Canyon, New Mexico. Seven of these corncobs were analyzed previously in a geochemical study aimed at determining the locations of the fields in which they were grown. We report radiocarbon dates obtained on these seven corncobs. Comparing the morphologies of the eight corncobs with other archaeological samples of corn from the San Juan Basin supports observations that Pueblo Bonito cobs are larger and have more kernel rows than some other basin samples. The radiocarbon dates preclude the possibility that these seven corncobs represent modern or historic period maize. The dates presented do not support a previous interpretation that there was a change over time in the locations where this corn may have been grown. Not ruling out other possibilities, the dates obtained, the special characteristics of this corn, and its presence in older rooms in Pueblo Bonito argue for continued use of Pueblo Bonito for special purposes over many centuries. In Pueblo belief, as among many indigenous agricultural cultures of the Americas, corn is an important source of sacred power.

Wood used in the construction of Chacoan great houses represents a class of bulk artifact collected and prepared for use in buildings that can be reasonably argued to be public structures. The organization of production is generally held to be within the framework of a corporate chiefdom, as defined by cross-culturally inspired position papers for the "Organization of Production" symposium on the Chaco phenomenon. The organizational requirements for the acquisition, processing, and transport of construction elements are discussed through the examination of harvest schedule, the description and comparison of beam treatments, and labor investment for the processing, transport, and stockpile management of the beams. The timing of harvest and the labor effort invested in construction wood is found to be different and more intense than in a sample of comparable-scale non-Chacoan buildings but within the means of self-paced, corporately motivated task groups operating under the parameters of seasonal household schedules. Because of the consistency of handling, and quality of treatment, we envision the development of skilled task groups, perhaps at the level of a formal fraternal society, under the guidance and organizing skill of a limited number of leaders or specialists. More centralized corporate direction may have been an aspect of organization for only a brief period after A.D. 1070.

The inventory and analysis of 4,294 pieces of wood remaining in Pueblo Bonito are described. This site, long a keystone for interpreting the Chacoan Phenomenon in the San Juan Basin of northwestern New Mexico, reveals a fascinating history in the procurement, use, and reuse of wood through time. The long use of the site portrays a complex picture of wood procurement for construction from the A.D. 800s through the early A.D. 1100s, and its reuse in both prehistoric and historic times. Major construction periods are tree-ring dated to the mid-A.D. 800s, between A.D. 1047 and 1049, and between A.D. 1077 and 1082. Many of the construction events appear causally related to decade-long wet periods, when food surplus could accumulate. The use of wood at Pueblo Bonito mirrors a larger system of cultural behavior important for our interpretation of the development and demise of the Chacoan system.

The appearance of pithouse settlements in the American Southwest that have multihabitation structures has been considered evidence for the emergence of "village" social organization. The interpretation that village systems are reflected in pithouse architecture rests in great part on the assumption that large sites correspond to large, temporally stable social groups. In this article we examine one of the best known pithouse settlements in the Southwest—Shabik’eschee Village in Chaco Canyon, New Mexico—and argue that the site may represent episodic aggregation of local groups rather than a sedentary occupation by a single coherent social unit.