Migration and Overpopulation Theory

Declining rainfall during the 1300s may have caused neighboring cultures to move out of the north and east and into the Salt River Valley, settling amongst the Hohokam.  The sudden increase in population would have seriously overextended Hohokam resources.  Archaeological evidence shows that the population at this time was malnourished, had overfished the Salt River, and had exhausted many other local resources.  This suggests that overpopulation caused depletion in resources, forcing the Hohokam to abandon their settlements.