Líl’wat Oral Traditions of Qw̓elqw̓elústen (Mount Meager): Indigenous Records of Volcanic Eruption, Outburst Flood, and Landscape Change in Southwest British Columbia

Indigenous oral traditions of the Líl̓wat Nation recount observations of Qw̓elqw̓elústen (Mount Meager), a Garibaldi Volcanic Belt volcano in southwestern British Columbia, Canada; and associated eruptive activity, mass-wasting, and outburst flooding. We present Líl̓wat observations relating to Qw̓elqw̓elústen’s ~2360 cal yr BP eruption and its aftermath, a devastating outburst flood down the Lillooet valley. The Copper Canoe story correlates with the event-sequence of pyroclastic damming of the Lillooet River and an outburst flood traveling far downstream, interrupting salmon runs and displacing people. Other stories suggest an eruptive plume and fumaroles. Recounted valley-floor changes, with proximal scouring and downstream filling of marshes allowing human resettlement, closely parallel and augment geological evidence, showing that oral traditions are equally important in holding landscape history. Oral traditions portray dramatic landscape changes, some by the Transformers, said to have traveled this land making imperfect things right. Geologically documented debris-flow delta progradation and infill of the upper 50 km of Lillooet Lake since ~12,000 cal BP underscore the land’s dynamism and the need for both sources to inform planning for future eruptive, mass-wasting, and flooding events. Traditional landscape knowledge, like Western science, is observational and evidence-based, though interpretations can differ given Indigenous belief in a sentient landscape, capable of acting with intention. Binding of stories to geographical locations has functioned as a mnemonic device to preserve orally transmitted information across many generations.