CASA GRANDE RUINS The History of Casa Grande Ruins National Monument

Hunting people are known to have inhabited the Southwest with Pleistocene animals. Excavations at Ventana Cave (Haury 1950), a shelter affording both weather protection and water in the southern Arizona desert, have shown human remains from at least late-glacial times; through a period of wild plant food gathering; to the pottery, corn agriculture, cotton textile, and shell jewelry of the Hohokam.

The Hohoka ("People who are gone" in Pima Indian language) were settled in the Gila and Salt River Valleys, farming by irrigation, and building one-room, wood and dirt houses by A. D. 700 (Gladwin and others 1937). By the tenth century A.D., after generations of work with their stone hoes and wooden digging sticks, hundreds of miles of canals were in operation; corn, beans, squash, pumpkins, and cotton were being grown; over 10,000 people were making their living from these desert valleys [2] (Schroeder 1940; 1953).

During the 12th century another group of farmers came to settle in the irrigated areas of the desert; they were a pueblo people, with some traits common to the subdivisions designated by archaeologists as Sinagua and Salado (Schroeder 1947), and with the distinctive red, black, and white Gila Polychrome pottery of the Salado. This movement of peoples from central and northern Arizona, a resettlement project which probably continued for several generations, added new types of architecture and pottery and new burial customs to the desert life. The architecture was to develop from post-reinforced dirt walls to massive walls of solid caliche which would support multi-room, multi-story dwellings typical of the Pueblo people; villages were to change from scattered one-room houses to compact blocks of rooms surrounded by a compound wall (Haury 1945: 207).

Representing the peak of this architectural development is the 14th century "Compound A" of Casa Grande National Monument, with its Great House towering above all other known prehistoric buildings of this area.

The Casa Grande was designed for height, possibly to compensate for the lack of natural elevations which would have enabled the farmers of the region to easily observe the needs for canal maintenance and water regulation—and the distant approach of unidentified people, who might be a raiding party. The tower room, 35 feet above the plain, stands on walls resting on hardpan five feet below the present ground level and four feet thick at their base; (A. T. Bicknell, personal communication, based on trenching done by Charlie Steen) these walls are part of the 5-room base of the tower, with the entire ground floor filled for additional bracing, and the 5-room plan carried up to the third-story set back. Details of wall load, weight distribution, and room dimensions were evidently well considered before construction began. The excellence of both design and construction is proven by its present existence, a dirt building still four stories high after some 500 years of neglect.

While in use, the Casa Grande commanded a view of the lower part of the main canal, whose intake was at a bend of the Gila River about 16 miles upstream (Larson 1926). As long as the canals carried enough water, to land which was productive enough, the Hohokam-Pueblo towns prospered. When the balance between people to be fed and food available became seriously disturbed, we don't know. Nor are we yet sure how much such other factors, as periods of drought, inter-town disputes over water rights, malnutrition and disease, and raids by enemy groups, may have affected the final decision. But by the end of the 15th century the walled villages were abandoned. When the Casa Grande was seen by Spaniards in the 1690's the caliche towns were in ruins and many of the canals filled by wind-blown sands; the only Indians in the vicinity were the Pimas, maintaining canals and villages of brush and mud houses close to the river.