Casa Grande and 480 acres around the ruins became the first prehistoric and cultural reserve in the United States in 1892 under President Benjamin Harrison. “Casa Grande” is Spanish for “big house”; the name refers to the largest structure on the site, which is what remains of a four-story structure that may have been abandoned by 1450. The structure is made of caliche, and has managed to survive the extreme weather conditions for about seven centuries. It was constructed using traditional adobe processes and holes in the walls align with the sun and moon to mark the summer solstice and the vernal and autumnal equinoxes.
Casa Grande is believed to have been built by the Hohokam who existed between 300 and 1500 CE, with cultural precursors possibly as early as 300 BCE. Hohokam societies received a remarkable amount of immigration and are recognized for their large-scale irrigation networks.
