Casa Grande Ruins is the first archeological site to be preserved by the federal government and the fifth oldest unit in the National Park Service. Set aside as a federal land reserve in 1892 and then as a National Monument in 1918, Casa Grande Ruins is a very special place, a place where history transcends 600 years of continuous occupation.
Archeologists have discovered evidence of wide-scale irrigation farming and trade which lasted over a thousand years and ended about 1450. Today the ancient ones are remembered as the Hohokam, an O'odham word meaning "Those Who Are Gone." The Hohokam abandoned the Casa Grande area around 1450 C.E., leaving no written language behind. Historic accounts of the Casa Grande begin with the journal entries of Padre Eusebio Francisco Kino when he visited the ruins in 1694. In his description of the large ancient structure before him, he wrote the words “casa grande” (or “great house”) which are still used today. More became known about the ruins with the later visits of Lt. Col. Juan Bautista de Anza’s expedition in 1776 and Brig. Gen. Stephen Watts Kearny’s military detachment in 1846.