US Geological Survey


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This is an unpublished manuscript that can be downloaded and read by those who find the embedded topics of some interest. We would appreciate the readers’ comments on any subject discussed in the manuscript. The email address of the first author is shown below. Parts of this paper (the isotopic and agricultural sections) will eventually be submitted for external publication.


Copyright ©2019 Larry V. Benson, Deanna N. Grimstead, John R. Stein, David A. Roth, & Terry I. Plowman.

August 12, 2019: By request of the first author, this paper has been withdrawn, as they have begun publishing extracts drawn from the original MS.


Some Southwestern archaeologists continue to ascribe to the hypothesis that Chaco was agriculturally productive to the point that it could support at least a few thousand full-time residents. This paper suggests an alternative hypothesis; i.e., Chaco was marginally productive and could only support a few hundred permanent residents. Isotopic analysis of mammal teeth found in trenches cut through platform mounds fronting Pueblo Bonito indicate the possibility that much of the meat consumed by Chacoan residents and visitors came from higher elevation sites bordering the San Juan Basin. We suggest that resident population estimates based on great house room numbers and small site numbers within the Canyon are overblown and that both types of structures were mainly used by visitors to the Canyon. Many of these visitors may have journeyed to the Canyon during annual pilgrimages, carrying excess maize and meat which was used to supplement the diets of Canyon residents. In this paper we provide information from a variety of disciplines including geochemistry, hydrology, climatology, foraging theory, and archaeology to support our hypothesis.