The Anasazi's Ancestors from 8,000 to 5,000 B.C.

The Early Holocene in the northern Southwest represents a long fluctuating trend of decreasing moisture. Mesic forests were gradually replaced by pinon and juniper woodlands while areas formally occupied by pinon and juniper gave way to grasslands and desert shrub. Paleoenvironmental data suggest that these changes were accompanied by a climate shift in which most moisture occurred in winter. Between 6,500 and 6,000 B.C., the rate of desiccation increased, and grasslands retreated towards the east to be replaced by semi-arid desert shrub. By 5,000 B.C., the climate in the northern Southwest was much like it is there today.

Archaeologists label the period beginning in 8,000 B.C. as the "Early Archaic." Unlike the earlier Paleoindian mammoth and bison hunters, Archaic people became less mobile, more dependent on a wide variety of local food resources, and more culturally diverse. Through the entire Archaic, people tended to follow the pinon-juniper woodlands as they retreated towards the north and into the richer valleys and basins found at higher elevations.

During the Early Archaic, a broad continuum of interacting cultures occupied a large area of the Southwest. Labeled the "Picosa Culture" by Cynthia Irwin-Williams, this early tradition was characterized by small sites with no structures. A study of projectile points by W. Wills of UNM suggests that people were increasingly focusing on local lithic materials, indicating a decrease in mobility, while the multipurpose and overdesigned quality of the points to a foraging lifestyle. Wills also notes that the designs of these points were consistent over a large area, indicating that Archaic populations were not competing with one another and not maintaining symbolic boundaries through the use of different projectile point styles.

However, although people in the Southwest during this time shared many features, regional differences did begin to develop as decreasing mobility led people to focus on unique local environments. Archaeologists believe that by 7,000 B.C., different traditions emerged. In western Arizona, southern California, and southern Nevada, unspecialized hunter-gatherers formed the San Dieguito-Pinto Tradition, while in southern Arizona and southwestern New Mexico, people of the Cochise Tradition increasingly hunted small mammals and ate plant materials processed using milling stones.

Most relevant to the prehistory of the Anasazi, however, was the development of the Oshara Tradition in the Four Corners area of the Southwest. There is some debate over the origins of the Oshara Tradition, for some archaeologists believe that the Cody Complex was gone by 6,000 B.C. and that the Oshara Tradition that emerges around 6,400 B.C. is so different from the Cody Complex that there must not be any connection between them. Whether this indicates actual population movements or not is difficult to determine with the available data, but there is some similarity between early Oshara cultural material and artifacts associated with Great Basin traditions to the north.

The first phase of the Oshara Tradition is known as the Desha Complex, which lasted from 6,000 to 5,000 B.C. primarily in southern Utah and northern Arizona. Cultural material associated with Desha people includes elongated side-notched points, basketry and sandals, and some groundstone. This artifact assemblage suggests that the Desha were moving on a seasonal basis and eating a variety of plants and animals. This was confirmed by a study of over 200 coprolites, or preserved human feces, that were recovered from Dust Devil Cave in New Mexico. These coprolites were analyzed by archaeologist Van Ness, who found a wide variety of plant and animal remains that suggested that the cave was occupied in the winter or the spring. In addition to a diet high in rabbit, a variety of plants such as dropseed, prickly pear, chenopodium, sunflower, and pinon were found in the coprolites. In a similar study by Matson and Chisholm, carbon isotope analyses of a Desha skeleton revealed a diet in which 40% of the protein came from C4 or CAM plants, perhaps from the many chenopod and cactus species found in the Southwest. Unfortunately, the study could not determine whether these proteins were obtained directly from the plants or from animals that ate C4 and CAM plants.

The Desha pattern of seasonal mobility and localized adaptation is readily apparent when one looks at other sites from the Four Corners area. In Sudden Shelter in Utah, archaeologists discovered a large quantity of groundstone and a variety of small seeds including chenopod species, amaranths, grasses, and cacti. However, mammal remains were a major focus, with 70% of meat coming from mule deer. At Cowboy Cave, groundstone and plant remains dominated, while fewer mammal remains and chipped stone artifacts were recovered. The emphasis here appears too have been on the processing of plants, and a study of coprolites from the cave showed that people had been eating sunflower seeds and dropseed. Overall, the picture of Desha life suggests that these Early Archaic people tended to focus on hunting at the high-altitude sites and gathering plant foods at the low-altitude sites. This is a pattern known as "seasonal transhumance," in which a group of people seasonally moves between two different environmental zones. In the case of the Desha, the evidence suggests that even though they regularly returned to the same area, they did not routinely occupy the exact same sites every year and therefore were likely associated with fairly large territories.

By the end of the Early Archaic period, attention shifted south to the central areas of the Colorado Plateau. Here a new tradition, the Jay Phase, developed between 5,500 and 4,800 B.C. Characterized by large, slightly shouldered points and well-made knives and scrapers, the Jay Phase represented a further decrease in mobility and a cessation of seasonal transhumance. People instead built base camps that were strategically situated at canyon-heads where three microhabitats converged, and they focused on the year-round exploitation of a fixed group of resources. As a result, their activities became more "logistical"; instead of wandering around and foraging for whatever food they might find, each excursion was more focused on obtaining a specific resource. For example, from their base camp, Jay Phase people might have focused on the low mesas to find grass seeds, or they might have gone to a specific pond in the mountains to hunt for deer, or they traveled to a special canyon to obtain raw material for making stone tools. The result was a series of specialized activity sites that were occupied very briefly and that now contain a very narrow range of artifacts, making it difficult for archaeologists to identify.

One remaining point of interest regarding groups in the later Early Archaic period is that their projectile points were extremely consistent over a large area. Some archaeologists believe that this stylistic homogeneity may indicate a correspondingly homogeneous social organization. This evidence suggests that Jay Phase groups interacted with one another over a fairly large area, perhaps developing exchange relationships that allowed them to acquire resources from far away.