Description
Research and documentation of late prehistoric exchange in the Far Southwest has received very little attention in the archaeological literature. Using a balanced program of ethnographic/ethnohistoric, and archaeological data, a preliminary assessment is made of the exchange network complexity in the region now known as San Diego County, Imperial County, and northern Baja California. Archaeological research was formulated and instituted for the Carrizo Gorge area of Anza-Borrego Desert State Park for the express purpose of testing the proposition of a late prehistoric communication route descending through the gorge. The probability of Carrizo Gorge being a portion of the communication network was alluded to in the ethnographic literature. Using current archaeological economic theory applicable to regional prehistoric exchange, data gathered from SDi-161 in Carrizo Gorge is compared with two other sites in similar cultural and natural environments in the local area. A correlation matrix based on Pearson's product-moment correlation coefficient is used to compare the sites. Interpretation of the statistical results suggests that Carrizo Gorge is very likely a portion of a late prehistoric communication network. Ten sites selected within San Diego County were subjected to a regression analysis using obsidian frequencies within the sites as dependent variables (Y) and distance from the regional Obsidian Butte source as independent variables (X). Interpretation of this preliminary analysis suggests the probability that the exchange system was directional and does not conform to the gravity model of monotonic decrement. The ethnographic/ethnohistoric data suggest that exchanged material moved throughout the late prehistoric region under discussion by four general mechanisms: 1. Seasonal Transhumance A. with possible pooling in the Peninsular Ranges 2. Direct Access 3. Premeditated Exchange Journeys 4. Incidental Traders The network was characterized by: (1) a large diversity of lithic, subsistence, and ideological exchange; (2) directional symmetry focused on the Cuyamaca/Laguna Mountains and the San Diego River System; and consequently (3) a complex network serving to link diverse lineages from the Sand Hills in Imperial Valley to the Pacific Coast, and south into Baja California. A research program for further investigation of the late prehistoric exchange system in the Far Southwest is presented as part of the discussion.
