Oregon Revised Statutes State Legislative Department and Laws § 171.068

(1) For purposes of ORS 171.060, 171.062 and 171.064, the county court or the board of county commissioners which shall fill the vacancy in the Legislative Assembly in a district created by reapportionment shall be the county court or board of county commissioners of each county any part of which is in the district that is created by the reapportionment and includes the residence from which the former Senator or Representative was elected.

(2) Each person nominated by a major political party to fill a vacancy in the Legislative Assembly occurring as described by ORS 171.051 in a district created by reapportionment must be registered to vote in the district from which the former Senator or Representative was elected and must have been a member of the same major political party at least 180 days before the date the vacancy to be filled occurred.

(3) This section shall apply only to a vacancy in the Legislative Assembly occurring after the primary election next following reapportionment and before a person has been elected and qualified to fill the vacancy.