Fig. 2. (A) Plot of radiocarbon dates from southern Northwest Coast archaeological sites, used as a proxy for human population size (adapted from Ames and Maschner 1999: Fig. 4a, summing dates by 400-year intervals); (B) Salmon Index, south–central Northwest Coast sites; (C) Cervid Index, south–central Northwest Coast sites; (D) Artifact accumulation, northern Columbia Plateau archaeological sites, used as a proxy for human population size (adapted from Miss 1985: Fig. 9-6, total artifacts/volume/duration of components, averaged for all components; FMR—fire-modified rock; Lithics—stone tools and manufacturing debris); (E) Salmon Index, northern Columbia Plateau; (F) Artiodactyl Index, northern Columbia Plateau. Time scale is radiocarbon years before present. Indices are ratios with values from 1–0 (e.g., frequency of salmonid bones /frequency of all fish bones; frequency of cervid bones/frequency of cervid + small mammal bones, and so forth). For the salmon index, 1 indicates an assemblage composed exclusively of salmon and 0 lacks salmon remains. See Butler and Campbell (2004) for more information.