Oregon Constitution Art. VII (Original) § 2

The Supreme Court shall consist of Four Justices to be chosen in districts by the electors thereof, who shall be citizens of the United States, and who shall have resided in the State at least three years next preceding their election, and after their election to reside in their respective districts: The number of Justices, the Districts may be increased, but shall never exceed seven; and the boundaries of districts may be changed, but no Change of Districts, shall have the effect to remove a Judge from office, or require him to change his residence without his consent.