Hohokam Impacts on the Vegetation of Canal System Two, Phoenix Basin

In 1850, the Phoenix Basin had been uninhabited for about 350 to 400 years. It was visited occasionally by hunting, fishing, or gathering parties from the Pima, Pee Posh, Yavapai or Apache, but the last people to have cleared farming fields, excavated canals, and built villages in the lower Salt River valley had been the Hohokam, and they had abandoned the area sometime between A.D. 1450 and 1500.

This timeline is important to archaeologists because it means that the desert vegetation in the lower Salt River valley had had more than three centuries to return towards a natural climax that was only minimally affected by human intervention. (In some places the abandoned canals continued to have a relict affect on vegetation as discussed below.) Archaeological evidence suggests that the composition and approximate distribution of plant communities in 1850 resembled those that had last existed in the basin at around A.D. 300 to 400, when the Hohokam were just beginning to grow in population size.