Oregon Revised Statutes Miscellaneous Matters Related to Government and Public Affairs § 199.790

(1) If an election for the purpose of establishing a new county is held, the Governor shall issue a proclamation declaring a new county created when, of the electors voting at the election, a majority of the electors residing within the limits of the proposed new county voted in favor of the creation of the new county.

(2) If an election for the purpose of changing county and city-county boundaries is held, the Governor shall issue a proclamation declaring the change in boundaries when, of the electors voting at the election, a majority of the electors in the area proposed to be transferred to the contiguous county and a majority of the electors in the contiguous county voted in favor of the proposed change in county and city-county boundaries.