This article reports the molecular composition of smoke particles people in SF Bay Area were exposed to during northern California wildfires in Oct. 2017. Major components are sugars, acids, aromatics, and terpenoids. These observations can be used to better understand health impacts of smoke exposure. Tracer compounds indicate which fuels burned, including diterpenoids for softwood and syringyls for hardwood. A statistical analysis reveals a group of secondary compounds formed in daytime aging.