Prehistoric Human Occupation
There is little evidence of either Paleo-Indian or Archaic occupation of this region, although it was likely used sporadically by these peoples throughout the prehistoric millennia. The nomadic lifestyle of the late Archaic peoples eventually evolved into one of increasing population groups and sedentism, especially as maize became central to subsistence around 500 B.C. By 200 A.D., the Canyon de Chelly area was occupied by peoples we now classify as Basketmaker II. These people made temporary and seasonal shelters, often in the natural protection of the canyon's abundant rock shelters. Many of these shelters could only be reached by scaling the rock face by way of hand-and-toe holds. One such shelter, Mummy Cave, contains evidence of continuous occupation from 200 A.D. through abandonment of the canyon around A.D. 1300.
By 500 A.D., the Basketmaker III culture had evolved. These people lived in small villages composed of several to many pithouses in the canyon bottoms and in the alcoves of the canyon walls. The Basketmakers practiced simple agriculture on the arable lands of the canyons, growing crops of maize and squash irrigated by the canyon streams. They also made baskets, sandals, and other woven articles of fine quality, which have been well documented in the archaeological record at de Chelly. Archaeologists consider these Basketmaker III peoples as representing the first emergence of a distinct culture, the Kayenta Anasazi.
The time period between 700 and 1100 A.D. encompasses the Pueblo I and II Anasazi periods. Above-ground masonry or jacal (wattle-and-daub) pueblo structures became prevalent, first as storage rooms, then later as residences. Pithouses and kivas continued to be important architectural designs. The de Chelly Anasazi added beans and cotton to their agricultural domain, and domesticated dogs and turkeys were kept in the settlements. The Anasazi became skilled weavers of cotton clothing and blankets. Pottery making and the use of the bow and arrow developed during these periods.
It is estimated that the population of Canyon de Chelly increased sixfold between 850 and 1150. This population boom was likely brought about by the success of agriculture in the canyon, which was aided by the favorable climate of this period. Studies of tree rings, fossil pollen and excavated plant fragments indicate that rainfall was especially high between 1050 and 1150. Dry farming on the upland plateaus around the canyons supplemented canyon farming, as did collection of wild plants such as pinyon nuts and cactus fruits, and hunting of wild game animals including rabbit, antelope and bighorn sheep. Pottery made in Mesa Verde, Colorado and Chaco Canyon, New Mexico found at de Chelly sites attests to trade with outside tribes. The use of rock shelters as habitation sites declined throughout this period, a trend which continued into the early Pueblo III period, up to 1250.
In contrast, late Pueblo III times (1250-1300) were characterized by intense cliff dwelling construction, ranging in size from a few rooms to over a hundred rooms and accompanied by circular kivas. In addition, many existing cliff dwellings were greatly enlarged. Population estimates for the main canyon during this period range as high as 800. Immigrants from Mesa Verde and Chaco Canyon, New Mexico moved into the area during this time, building impressive pueblos in the style of their respective homelands. Despite immigration and increased construction, population levels began to decline, due in part to changing environmental conditions. Agricultural productivity deteriorated as precipitation decreased, periodic droughts struck, the water table lowered, and soil erosion increased.
Although the Anasazi had enjoyed relatively peaceful lives for most of their history, this began to change in the eleventh century. It is not clear whether nomadic Athabaskan or Shoshonean Ute tribes began to raid the area from the north and east or if the conflict was internal, but by the late 13th century site selection appears clearly to have been based on the need for defense. Many focal sites were strategically built on steep hilltops or high on canyon walls in such a way that each was visible to the others for communication and coordination. A number of burials bearing signs of violent death have been found in the canyons.
The last construction tree-ring date in Canyon de Chelly is 1286; by the end of the thirteenth century the region had been entirely abandoned. As with the similar abandonment of the entire Four Corners Region, it is not known the exact reason or combination of reasons leading to this exodus. Drought, natural resource depletion, arroyo cutting and warfare are all possible explanations. The Anasazi of Canyon de Chelly likely joined other Anasazi immigrants in new pueblos to the south and east, where their descendents still live today.