ORS 307.180: Property of Indians.

The real property of all Indians residing upon Indian reservations who have not severed their tribal relations or taken lands in severalty, except lands held by them by purchase or inheritance, and situated on an Indian reservation, is exempt from taxation. However, the lands owned or held by Indians in severalty upon any Indian reservation and the personal property of such Indians upon reservations shall be exempt from taxation only when so provided by any law of the United States.