In the first century AD, the Hohokam moved along the Salt River in Arizona and began an irrigation farming system.
Around 100, people from Mesoamerica migrated north and took residence in the Four-Corners area, the mountains of New Mexico (the Mogollons) and central Arizona. They would become known as the Hohokam, the Mogollon and the Anasazi.
The Hohokam settled along the Gila and Salt River drainage in central Arizona around 350. They occupied these sites until around 1100.
Around 400 the Anasazi culture emerged in northern Arizona and the Four-Corners area. Their sites all had similar design. They were centralized sites surrounded by large cultivated fields with one-story houses of multiroom dwellings. They grew two crops a year of maize, beans and cotton. They built irrigation canals and knew how to tap underground water by digging wells.
Around 750 AD Hohokam expanded their culture from central to north Arizona up the Verde and Agua Fria Rivers. These rivers were used as Hohokam immigration routes. It is possible that Hohokam expansion was fuelled by their successful irrigation and agricultural techniques that produced large food surplus that in turn allowed the population to increase. This expansion went on until 1300 when Hohokam centres declined. They are thought to be the ancestors of the Pima and Papago.
Archaeologists have shown that the oldest wooden beams used for the construction of Pueblo Bonito at Chaco Canyon, New Mexico, were cut in 919. At first Pueblo Bonito rose three stories and contained over 100 rooms. Construction was halted for almost a century but a second phase began in 1019 which was completed in 1067. It was then five story high and had 650 rooms. Seven more great pueblos were built at the same site.
Mesa Verde in Colorado reached its high point between 110 and 1300. its biggest dwelling, Cliff Palace, had 220 rooms and 23 kivas and housed as many as 350people. By 1300 it was abandoned its residents having migrated to the Hopi/Zuni areas and to the Rio Grande Pueblos.
Between 1119 and 1180 the Chaco Canyon people built an elaborate road system, about 500 miles, to link outlying communities to the central site at Pueblo Bonito. There were in fact about 70 outlying settlements as far as 100 miles away.
The Hohokam reached their highest level around 1125. The present site of Phoenix, Arizona, was settled around 500 BC and expanded greatly around 800 AD. With 300 days of sun a year it was a good agricultural country. The Hoholam built hundred of miles of irrigation canals to increase their maize, beans, squash and cotton production. Sometimes around 1350 the canals and the fields were abandoned possibly because the water table dropped, a long period of drought, salinization of the soil or the collapse of the supporting Toltec culture.