Archeologists have found evidence that the Hohokam Culture, now refered to as the Ancestral Sonoran Desert people, who built the Casa Grande also developed wide-scale irrigation farming and an extensive trade alliance, one which possibly lasted a thousand years or longer, came to and end between 1350 to 1450 CE.

At these sites have been found earthen buildings, red on buff pottery, and extensive canals, all of which have been called Hohokam Cultures sites. However, this name is not the name that the people called themselves, but a cultural label composed by moderns. Instead, the people who built these ruins were most likely the ancestors of the O′Odham, Hopi, Zuni and other people who live in the area now.

Nevertheless, the ancient people were travelers from Mesopotamia and journeyed to here during the second migration across the Beringia Land Bridge.

Casa Grande, which when translated is the Great House together with its surrounding compound was likely built by this culture quite a long time earlier, as the wise men of today state, even as early as 1500 BCE and was used by this culture up until some time after 1350 CE. Further, this structure is one of the largest prehistoric structures ever built in North America, and even so, the real purpose for the building remains a mystery.

The ancients who lived here apparently discovered that as their villages grew, farm land adjacent to the rivers was becoming scarce. Therefore, to bring water to land farther away from the rivers, it was necessary to dig canals. These canals could have been dug as early as 1500 BCE, and was a practice that they would have continued to use throughout their generations.

Further, hundred of miles of prehistoric irrigation canals have been discovered within the Gila River valley, the Salt River Valley near Phoenix, the Santa Cruz River Valley near Tucson, and on the American Indian reservations throughout southern Arizona.