Oregon Revised Statutes Counties and County Officers § 202.120

(1) The county court of the new county may temporarily fix the county seat, and such location shall remain the county seat until the first general election thereafter, when the electors of the new county are empowered to vote for and select the place of county seat in the manner provided by law.

(2) Immediately after the selection of the county seat either by the county court or by the canvass of the returns of votes cast at the election for that purpose, the county court shall issue its proclamation and publish the same in a newspaper published in the new county, if there is one, and if not by posting a copy of the proclamation in each election precinct in the county announcing the selection and location of the county seat.