POPULATION DYNAMICS AT THE GRASSHOPPER PUEBLO, ARIZONA'

Abstract

THERE IS A LONG HISTORY of interest in the study of extinct populations, sometimes called "prehistoric demography" or "archaeological demography." Most studies have focused on regional population size and trends through time and their explanation. Analyses of a single population at one community are rare. This paper discusses one effort at assessing the dynamics of population at one prehistoric community, the Grasshopper Pueblo, located in east-central Arizona. A long range program of archaeological research is being conducted at the site by the University of Arizona through the Archaeological Field School. This program is sponsored jointly by the Department of Anthropology and the Arizona State Museum and has been supported by the National Science Foundation since 1965. The Grasshopper Ruin, a fourteenth century pueblo, is an example of what some have called "Late Mogollon" or "Prehistoric Western Pueblo" culture. It consists of several main room clusters separated by a presently intermittent stream and surrounded by smaller groupings of rooms. There are approximately 500 rooms at the site. Space does not permit a discussion of the range of problems that we are attempting to solve in our research nor the sampling design. But one aspect of our work, the "Cornering-Growth Project," has provided us with the relative construction sequences for all the rooms at the community. These data provide a basis for a study of population dynamics. We may now describe the Grasshopper Ruin as a masonry pueblo of about 500 rooms distributed among 12 room blocks and 21 smaller groupings of rooms and construction units. The main part of the site consists of three large room blocks located on either side of the original channel of the intermittent stream. On the east side is Room Block 1 with 93 rooms; the west unit consists of 2 room blocks, Room Block 2 on the west bank of the stream with 92 rooms and the Great Kiva, and Room Block 3 with 99 rooms. Together, these room blocks bound the larger Plaza I and the smaller Plaza II. Access from the exterior was through two corridors, one to the south of Plaza I, and another to the east of Plaza II. Additional room blocks and smaller units of rooms are located adjacent to the 3 largest room blocks and on the surrounding low hills. The initial construction at the site took place in the last quarter of the 13th century. This we call the establishment period, A.D. 1275-1300. Following this, massive construction was carried out at the site. This period we label the expansion period and it appears to date from A.D. 1300 to A.D. 1330. Well more than half of the tree-ring dates from Grasshopper cluster during this period, and many of the central three-room blocks on either side of the stream were built by A.D. 1330. For example, the corridor south of the Plaza I was roofed in 1320, indicating that the construction had proceeded in the southern parts of Room Blocks 1 and 2 to that point. Dating of the building sequence after A.D. 1330 is less secure, but many of the outliers seem to have been built after this time. We have been fairly successful in controlling the time of construction and the relative time of abandonment for the 70 rooms we have excavated to date.