Oregon Revised Statutes Elections § 249.205

(1) If the only candidate nominated to a nonpartisan office dies, withdraws or becomes ineligible, or if a vacancy occurs in the nonpartisan office after the 70th day before the nominating election and on or before the 62nd day before the general election, a candidate for the office may file a declaration of candidacy in the manner provided for nonpartisan office or shall be nominated by nominating petition in the manner provided for nonpartisan office.

(2) The Secretary of State by rule may adopt a schedule for filing nominating petitions or declarations of candidacy under this section. The schedule may specify the period within which nominating petitions or declarations of candidacy must be filed after a vacancy occurs.