When SFI’s founders took up the challenge of developing a predictive science of complex systems in 1984, some of them already had in mind the utility of such an approach to solutions for longterm human problems. Murray Gell-Mann had a lifelong interest in archaeology and matters of deep history. Robert McCormick Adams was a key contributor to the study of the evolution of civilizations in both Mesopotamia and Mesoamerica. Could not the deep-time perspective and the solidly material record afforded by archaeology provide the data to test the implications of complexity theory for understanding the emergence of new forms of human organization? Surprisingly, the first major SFI initiatives did not involve the study of the first states and empires, what anthropologists, archaeologists, and historians have termed “complex societies.” Instead, perhaps because of the chronological precision and the year-to-year record of rainfall (crucial for village farmers in a semi-arid environment) provided by tree-ring studies, or perhaps because of the insight provided by the living descendants of the earlier Pueblo peoples, or perhaps because SFI is located in the North American Southwest, our first major archaeological study was of emerging forms of organization in our own backyard.