2015 ORS § 163.525¹
Incest

(1) A person commits the crime of incest if the person marries or engages in sexual intercourse or deviate sexual intercourse with a person whom the person knows to be related to the person, either legitimately or illegitimately, as an ancestor, descendant or brother or sister of either the whole or half blood.

(2) Incest is a Class C felony. [1971 c.743 §172]