Arizona: Casa Grande Ruins

This is the site of a large, unusual multistoried structure, the Casa Grande, built by the Hohokam people around 1350 c.e. Now protected by a steel shelter, the thick walls of the Casa Grande are clearly visible in the distance as visitors approach the monument, which for centuries has been used by travelers as a landmark and meeting place. Surrounding the Casa Grande are the ruins of one or more Hohokam villages that are open to visitors. Park rangers are available on the site to answer questions about the monument and the daily lives and culture of the Hohokam.



Site Office

Casa Grande Ruins National Monument

P.O. Box 518

1100 Ruins Drive

Coolidge, AZ 85228

ph.: (520) 723-3172

fax: (520) 723-7209

Web site: www.nps.gov./cagr/

Who were the people who constructed and then soon abandoned the Casa Grande? For what purpose did they build the unique structure? Despite the influence of Mexican peoples evident in their architecture, crafts, and irrigation techniques, the Hohokam (a Pima word meaning “those who have gone”), researchers believe, were descendants of the very early desert culture known as Cochise, and they shared ancestry with the Mogollon peoples, with whom they were closely linked in the beginning phases of their culture. Differences developed when the Mogollon moved into mountainous areas, but the two groups continued to interact and share cultural traits throughout the Hohokam’s residence in the Gila River Valley.



Origins of the Hokokam

The Hohokam apparently moved into the Gila Valley between 200 and 300 c.e., and lived there successfully and peacefully for about eleven centuries. By 600 c.e., Hohokam culture was already highly developed, and, according to some researchers, possibly near its peak. The people were producing fine crafts from shell and stone, their irrigation systems were in place and extensive, they had built a number of ceremonial ball courts, and their red-on-buff pottery had already become quite specialized.

Until the twelfth century, at almost the end of their history in the area and around the time that they built Casa Grande, the Hohokam lived in huts made of mud and sticks. For hundreds of years the traditional Hohokam village consisted of clusters of two to six grass-roofed, pole-and-mud-walled houses, near a source of water. Adobe-style construction such as that found in the Casa Grande compound was a late development in Hohokam culture, one possibly introduced through contact with the Salado people who lived north of the Hohokam, near the Tonto Basin.

By the twelfth century Hohokam culture had already begun to decline. Around this time the Hohokam appear to have come into contact with pueblo-based people, with whom the Hohokam may actually have shared some of the same villages. The Hohokam apparently kept their own customs for a while, such as living in pit houses and cremating their dead, while the pueblo people lived alongside them in adobe compounds and buried their deceased. By the time of the building of Casa Grande, however, the Hohokam appear to have begun living in huts above the ground (as ruins around Casa Grande suggest) and burying their dead. Persons selected for burial may have been members of an elite or priestly group. Whatever the true explanation, Hohokam skeletons do exist.



Canals in the Desert

To survive in the desert, the Hohokam depended primarily on the extensive system of irrigation canals they constructed, a sophisticated system that was the first of its kind in the Southwest. From the top story of the Casa Grande, one can see, about sixteen miles away, the lower section of the main canal that sustained local residents.

Through satellite photographs, it is now known that in the Phoenix area alone the Hohokam built more than six hundred miles of canals that diverted water from the Gila and Salt Rivers. The design of the canals–deep and narrow to minimize evaporation–indicates a sophisticated understanding of the irrigation needs of their environment.

Irrigation enabled the Hohokam to grow corn, beans, squash, cotton, and pumpkins. The people also ate local animals such as fish, river clams, rabbits, deer, and probably small rodents. Corn prepared in a variety of ways was likely the mainstay of the Hohokam diet, and also the cause of some health problems. Researchers who studied Hohokam skeletons from a different site found that tooth and gum disease was common, probably due to grit from the stones used to grind corn that got stuck in the gums and around the teeth. They also found signs of osteoporosis in many of the older women, and a fair amount of arthritis throughout the population.



Appearance and Customs

Physically, the Hohokam men were athletically built, with strong upper torsos, as one might expect in a people who survived through manual labor. The skeletons showed that the women, who were probably the grinders of the corn, had especially well developed hands.

Clay figurines found at their dwellings give us some clues about the appearance of the Hohokam. Cheek and lip plugs were popular, as were body paint or tattoos, and they wore a great deal of jewelry, including earrings, hairpins, pendants, bracelets, and rings. The Hohokam clearly were an artistic people. They made exquisite jewelry from jet, shells from the Gulf of California, and turquoise, and developed a unique etching process that probably involved using acids fermented from cacti.

The Hohokam also excelled at chipped, ground, and carved stone work, which they used to create a wide variety of miniature animal figures, such as birds or frogs, from thin pieces of stone or shell, as well as rectangular flat palettes with decorative borders. Hohokam craftsmanship also shows itself in finely crafted, long-bitted axes made from hard black stone. The Hohokam are also known for their characteristic cream- or buff-colored pottery painted with red designs.

Sports, possibly with ritual or ceremonial significance, were also part of Hohokam culture; some two hundred ball courts have been found in Hohokam sites, including Casa Grande. These ball courts, sunken oval fields, are another indication of Mexican contact or influence, since similar courts existed throughout prehistoric Mexico. No one knows precisely how the game was played, but there is on a wall of each of these courts a high stone ring through which players probably tried to pass a ball. The Mexican version of the game apparently forbade players from using their hands or feet when handling the ball; these rules may have been true for the Hohokam games as well.



The Mysterious Casa Grande

The greatest mystery left behind by the Hohokam Indians, however, is Casa Grande itself, a structure quite unlike anything else in the Southwest. What was its function? What was its purpose? Constructed between 1320 and 1350 c.e., the edifice was already in ruins in 1694, when Father Eusebio Kino, a Jesuit missionary, came upon it while exploring areas visited by Coronado one hundred years previously. In his journal, Father Kino wrote,

I went inland with my servants and some justices of this Pimeria, as far as the casa grande, as these Pimas call it, which is on the River of Hila that flows out of Nuevo, Mexico. . . . The casa grande is a four-story building as large as a castle and equal to the largest church in the lands of Sonora. . . . Close to this casa grande there are 13 smaller houses, somewhat more dilapidated, and the ruins of many others, which make it evident that in ancient times there had been a city here.

The unusual structure, which is more suggestive of Mexican than Southwestern architecture, sits in the midst of what appears to have been a Hohokam village, in a compound surrounded by an adobe wall approximately 420 feet long, 230 feet wide, and originally 7 or 8 feet high. The Casa Grande itself is about 40 feet long and 60 feet wide, with walls that are deeply trenched into the ground and taper from a base thickness of almost 5 feet to an upper thickness of about 1.5 feet.

The walls are made from caliche earth, a subsoil of the desert that has an especially high lime content. The mud for the walls was probably mixed by hand on site in a process similar to contemporary concrete mixing. The construction most likely involved the use of a framework, made of canes or poles and woven together with grass or reeds, that formed an open trough with two parallel surfaces. The workers would prepare the mud within these frameworks, which were about five feet long and three or four feet apart, and then remove the frames when the adobe was dry. The walls now look as if they were made of bricks, but the vertical lines in the surface are actually just cracks in the adobe.

Most of the Casa Grande structure is technically just two stories high. Yet the building sits on five feet of baseline fill, and this essentially adds another story to it. There are five rooms, with the central room reaching yet another story higher than the outside rooms. Thus the building varies in height from about twenty feet around the perimeter to at least thirty feet in the central tower.

The Casa Grande originally had a timbered ceiling built from more than six hundred roof beams of juniper, white fir, mesquite, and ponderosa pine. Since much of this wood was not available in the immediate area, the Hohokam must have transported it from more than fifty miles away.

The Casa Grande would have made an excellent sentry station, lookout tower, or possibly a fortress, although no signs of warfare exist in the area. Because there are even, round openings in the highest part of the building that provide specific views of constellations, the night sky, and the setting sun of the summer solstice, many people believe that Casa Grande functioned at least in part as an astrological observatory. Researchers are confident that all the early residents of the Southwest used some type of calendar, but are not sure whether these other cultures also erected structures such as Casa Grande to serve as observatories. Casa Grande could also have been an administrative facility, a palace, a large residence, a storage house, or a multipurpose facility.

The entire Casa Grande compound, like other Hohokam compounds, includes the remains of smaller structures of varying size, and thereby differs greatly from standard Southwestern pueblos. Pueblos are constructed in more egalitarian fashion, with rooms of equal size and no single large structure dominating the dwelling site. Since the physical design of the structure in which people live and work often reflects the nature of their society, the Hohokam may have had a more stratified or hierarchical society than other Indian peoples of the Southwest. Hohokam architecture also suggests an additional link to central Mexican peoples, who constructed similar compounds.

With its thick walls and solid construction, the Casa Grande was clearly built to be a permanent structure, and indeed it has withstood extreme variations in desert temperatures for nearly seven hundred years, most of the those years without protection. Unfortunately, Casa Grande far outlasted the Hohokam’s need or use for it. Despite the great efforts it must have taken to build the Casa Grande, the Hohokam used it for only about one hundred years. By 1450 the Hohokam had left the area, abandoning the Casa Grande compound and other dwellings in the region.



Departure of the Hohokam

Experts speculate that, like other Indian peoples in the Southwest, the Hohokam left the area because the land could no longer sustain their population. Possibly, their complex irrigation system failed as a result of lateral erosion of the Gila River, or perhaps the land itself became salinized from the extended use of irrigation. The climate may also have changed. Regional evidence indicates that periods of drought seem to have alternated with severe flooding during the final years of Hohokam residence in the area.

No one knows where the Hohokam went after leaving the Gila River Valley, but some experts speculate that the Pima Indians, who still live near Casa Grande, may be their descendants.



A Landmark for Travelers

Following Father Kino’s discovery of Casa Grande, the site quickly became known to westward-moving pioneers, soldiers, other explorers, and numerous tourists. Because it was easy to see from a distance, people used it as a landmark and meeting place. There was even a Southern Pacific Railway train station erected just twenty miles away from Casa Grande by 1880; it helped to increase tourism dramatically.

The popularity of Casa Grande had negative consequences. By the time archaeologists were able to study the structure and surrounding compound, numerous people had carved their names in the walls, vandalized and disturbed the site, and strewn the entire area with the remains of pots and other artifacts in their search for souvenirs. For this reason, it has not been possible to do an accurate study of the Casa Grande ruins.

Fortunately, the historical and archaeological significance of the site was recognized before it was damaged beyond repair. In 1887 to 1888 some of the most famous Southwestern archaeologists and explorers, including Frank H. Cushing, Jesse Walter Fewkes, Adolph F. Bandelier, and Frederick Webb Hodge, visited Casa Grande. Their attentions spurred efforts to designate the area as archaeologically significant, and in 1892 the federal government declared 480 acres around Casa Grande a Federal Reserve under official protection. This made Casa Grande the first archaeological preserve in the United States.

During the previous year, 1891, the first clearing, excavation, and stabilization of the ruins were conducted by Cosmos Mindeleff under the auspices of the Smithsonian Institution. The Smithsonian also studied Casa Grande from 1906 to 1908. Other excavations have been conducted by the Southwest Museum, the Los Angeles County Museum, and the National Park Service. In 1918, Casa Grande became an official National Monument.



For Further Information

  • Kidder, Alfred Vincent. An Introduction to the Study of Southwestern Archaeology. New Haven, Conn.: Yale University Press, 2000. This edition offers a new essay by Douglas W. Schwartz. Provides comprehensive information about the lower Gila Valley, with particular emphasis on the cultural wares of the people who inhabited the region. There is an excellent photograph of a model of the excavation of the complete Casa Grande ruin, which shows the structure in relation to the compound within which it sits.
  • McGregor, John C. Southwestern Archaeology. 2d ed. Urbana: University of Illinois Press, 1982. An in-depth chronological study of the major early cultures of the Southwest, with extensive information about the pottery and other artifacts the cultures left behind. Photographs, numerous illustrations, and maps add to this thorough history and reconstruction of prehistoric life in the Southwest.
  • Noble, David Grant. Ancient Ruins of the Southwest: An Archaeological Guide. 2d rev. ed. Flagstaff, Ariz.: Northland Press, 2000. Offers a thorough, yet concise look at the prehistoric cultures of the Southwest. Noble provides a brief history of each of the cultures, a short explanation of the significance of each historical site included in the book, and excellent photographs and simple maps.
  • Wilson, Josleen. The Passionate Amateur’s Guide to Archaeology in the United States. New York: Macmillan, 1980. Offers brief descriptions, maps, and photographs of archaeological sites throughout the country.