The Hohokam were a people who occupied the greater part of central and southern Arizona for more than a thousand years. They have been primarily noted for their development of irrigation and their construction of elaborate water control and distribution systems. But like the Ancestral Puebloans to their north, Hohokam culture went through several phases over the years, beginning with nomadic hunter-gatherers and proceeding through the development of pithouses, above-ground dwellings and finally multi-story pueblos. However, around 1350 CE a great drought set in all across the southwest and the centers of Hohokam culture disappeared as the people migrated to areas with more water and less heat.
Major Hohokam centers that have been identified are Snaketown, Casa Grande and Pueblo Grande. Snaketown was abandoned around 1050 CE and most of those people moved to the area of Pueblo Grande. Pueblo Grande was built around the confluence of the Gila and Snake Rivers in what is now the Phoenix basin.
Evidence of a culture from which the Hohokam may have evolved has been found in the Tucson basin. That evidence indicates a culture that began more than 3,000 years ago but most archaeologists are agreed that the Hohokam culture emerged around 300 CE. Their pueblos were located at the crossroads of major trade routes connecting the Mogollon to the east with the Pitayan and the Pacific coast to the west, and the Trincheras in Mexico to the south with the Ancestral Puebloans to the north and east. With influences from their trading partners showing everywhere, it is thought there was a lot of immigration and trade to and through the Hohokam centers. By 1300, Pueblo Grande was probably the most populous city in the Southwest. By 1450, the Great Drought had been on for 100 years and everything was abandoned. Archaeologists think that most of the people migrated to cooler, wetter areas in the surrounding mountains and are the ancestors of todays Tohono O'odham and Pima peoples. Some went northeast into the Salado area and merged with those people.
When the Apache first came into the area around 1500 CE, there was virtually no one to oppose them until the Spanish came along in the 1530's.
Some irrigation systems built by the Hohokam are still visible from space. Some sections of them have been dug out and are still in use in local irrigation systems.