Oregon Revised Statutes Public Health and Safety § 450.620

(1) When the governing body of each affected entity has adopted or approved a resolution pursuant to ORS 450.615, the governing body of the affected entity having the largest population according to the most recent federal decennial census shall call a joint assembly of the governing bodies of the affected entities. The governing body calling the joint assembly shall specify the time and place of the assembly. The secretary of the governing body shall give notice of the assembly to each member of the governing body of each affected entity. The notice shall be given by certified mail.

(2) At the joint assembly, a majority of the members of each governing body constitutes a quorum for the transaction of business.

(3) The assembly, by a majority of all members present, shall adopt an order calling an election in each affected authority. The order shall include the matters specified in ORS 198.745.