Fig. 1.

(A) Study sites on northern Quadra Island, British Columbia, showing clam garden sites (blue dots), large midden settlement sites (yellow diamonds), and sampling sites (red stars; numbers 1 to 5 correspond to SI Appendix, Table S3). (B) Clam gardens, Quadra Island. Clam garden built on soft sediment showing wall, clam garden terrace, and ∼9,000-y-old midden. Living and dead (paleo) butter clams were collected from the clam garden terrace and the shell midden. Image courtesy of Mark Wunsch (Greencoast Media, British Columbia, Canada).