Oregon Revised Statutes Shipping and Navigation § 777.155

Upon a petition of the electors filed with the board within 10 days after the date of a boundary or name change order a board shall subdivide the port. Such a petition shall be signed by electors registered in the district equal in number to at least 25 percent of the electors who voted at the last port election. The board by resolution shall divide the port into five subdistricts approximately equal in population. Not later than the 10th day after the resolution is adopted, the secretary of the board shall file a certified copy of the resolution with the county clerk of each county in which the district is located.