The predecessors of the Pueblo and Navajo tribes developed complex irrigation systems. While most texts likely list the Hohokam as a tribe responsible for complex irrigation, a 2009 Chicago Tribune article details a recent find of a much more extensive irrigation system in Arizona, that is likely the work of the Mogollon from Mexica. My guess is that most high school level texts are looking for Hohokam as the answer--if your text is copywritten after 2009, check the index for Mogollon to see if perhaps that is the answer.