Casa Grande National monument in Arizona; photo by Sirrobin33 on Wikipedia (use permitted with attribution / share alike).
Representative State Soil of Arizona
Casa Grande soil is the unofficial state soil of Arizona (each state in the United States has selected a representative state soil, and twenty state legislatures have designated these representative soils as official state symbols). All State Soils
The Casa Grande series was first identified in 1936. It is named after the city of Casa Grande and the nearby Casa Grande National Monument, home of a large earthen building constructed by the Hohokam Indians nearly 1,000 years ago. The Spanish words “Casa Grande” mean “Big House.” Native Americans used irrigation to remove excess salts from Casa Grande soils and raised cotton, grain, and vegetables on these productive soils, much as farmers do today.