Fig. 10. Population growth in the Lower Salt River valley of the Hohokam region. Population estimates for the Hohokam region are primarily based on previous work by Doelle (1995, 2000), who estimated population by placing all large sites across the region into a number of site size classes and defining a momentary population estimate for each size class based on the best-known examples in each category. He then used the existing information from archaeological surveys across the region to estimate roughly what proportion of the sites in a given time period are likely known. This information was used to create conversion factors that attempt to account for sites missing from the database. We used Doelle’s original procedures, but incorporated new information on specific sites and time periods into the database, altering the previously published estimates. The dotted portion of the line represents a time period for which there are few data. For our purposes, we assumed that the population increased gradually during this time to the levels estimated for the better-known period at around AD 1200.