Around 5500 BC, the Archaic people were the first inhabitants of the Casa Grande area in south-central Arizona. The Hohokam arrived in 300 AD. Also called the Ancient Sonoran Desert People, they were master architects of building canals from the Gila River for irrigation. When channeling water became increasing difficult, these Native Americans moved out circa 1450 AD. The ruins they left behind are fascinating. An example is the Great House seen in the background. On the right are the remains of another structure in the compound. In 1892, President Harrison signed into law the first federal protection of a prehistoric site in the U. S. The Casa Grande Ruins National Monument in Coolidge, Arizona is managed by the National Park Service. The park is well worth a detour in order to visit.