Rethinking the Pueblo I Period in the San Juan Drainage: Aggregation, Migration, and Cultural Diversity

The Pueblo I period (A.D. 750–900) in the northern Southwest was a dramatic time that witnessed large-scale population movements and the formation of the first large pueblo villages. By A.D. 860, there may have been more than 10,000 people settled in villages north of the San Juan River in southwest Colorado and southeast Utah. The populations of these villages appear to have come from at least two distinct cultural backgrounds. By A.D. 890, the population of this region had declined by at least two-thirds. Migration of substantial village populations to the south must be considered in any explanation of developments in the subsequent Pueblo II period, including the Chaco phenomenon.