Geophysical Surveys of Southern Pacific Northwest Coast Plankhouses

Geophysical and remote sensing surveys of Pacific Northwest Coast plankhouses, sweathouses, and other architectural features have been a growing component of Pacific Northwest Coast archaeological studies. Most of these studies have focused on coastal plankhouses with associated shell middens, especially in British Columbia. Limited geophysical examples exist of Pacific Northwest Coast architectural features from the southern region, including northern California and Oregon, especially in riverine settings. In this study, we integrate ground-penetrating radar and magnetic gradiometry to document subsurface features in collaboration with the Tsnungwe Council. Our findings, based on our interpretations of the observed data but not ground-truthed at this time, document subsurface features ranging from ~2 m wide pits to large rectangular plankhouses ~6 m wide and 12 m long. These houses include central subterranean pits, which contain a hearth, that are ~5 m wide. Our findings support the interpretation of a large multicomponent village site with several plankhouses present, providing a unique example of southern Pacific Northwest Coast Indigenous architecture. Future ground-truthing efforts may confirm and/or revise these interpretations.