Beyond culture history: Coast Salish settlement patterning and demography in the Fraser Valley, BC

• Our large radiocarbon data set, demographic model, and division of settlements into types, reveals shifts in socio-political complexity and interaction that would otherwise be obscured.
• Our mapping of settlements through time indicates long-term connections to both specific places (sites) and to more general culturally and ecologically important landscapes.
• Our data show how extant cultural historical phases can obscure temporal and spatial variability key to understanding complex and ever-changing social interactions.
• Our modeling indicates fluctuations in population throughout the Holocene with a statistically significant increase in population between ∼800 and 600 cal BP.
• Against a backdrop of relatively stable population, our settlement data indicate continually changing settlement strategies reflecting periods of both social aggregation and dispersal.

The florescence of large, regional radiocarbon data sets allows archaeologists to examine fine-scale, local changes in demography and settlement that are not tied to regional culture historical frameworks. We compile 599 radiocarbon dates from 95 archaeological sites in the Fraser Valley of British Columbia and use two complimentary approaches to explore how populations are distributed over time and across the region. First, we apply a summed probability distribution model to the dataset; this model indicates that populations generally increased over the Holocene with a significant rise ∼800–600 years ago. We then divide our data into 250-year periods and classify each site based on the number of houses, as a large settlement, small settlement, or camp for every period. We observe that the relative numbers of these site types fluctuate through time, and hypothesize that the larger fluctuations indicate changing patterns of social aggregation and dispersal, and settlement abandonment and reoccupation. Through time we see an increase in the number of sites overall, but with considerable variation in the relative number of site types. We see an underlying stability in settlement organization indicative of long-term cultural continuity and place-based identities linked to both specific sites and general locations within the region.