Agriculture and community in Chaco Canyon: Revisiting Pueblo Alto

The Bonito Phase (ca. AD 860–1140) in Chaco Canyon is widely recognized as one of the primary sources of information about emergent social complexity in prehispanic North America. Large masonry buildings called “great houses,” such as Pueblo Bonito, are iconic symbols of the rapid rise of a powerful society based on the ability to harness labor to prolonged construction projects. It is clear that the political forces at work during the Bonito Phase had an agricultural foundation, presumably in the financing of construction through food surpluses, but the actual nature of farming in Chaco is surprisingly opaque to archaeologists. Indeed, many researchers have concluded that farming in Chaco Canyon was too constrained by poor soils to have supported the dynamic developments associated with the massive stone structures and extensive trade systems of the Bonito Phase. The popular perspective that Chaco was mysterious or enigmatic is largely a response to this view of the canyon as agriculturally marginal. In this study we argue that a predictive model of potential agricultural productivity that includes other portions of the canyon besides the floodplain indicates that Chaco was not marginal for farming. The results of this analysis suggest that great house communities may have been sited to control local production zones and that some great houses may have been linked to others in order to manage multiple agricultural areas.