Oregon Revised Statutes Counties and County Officers § 202.150

(1) All public buildings, records or other public property within the limits of the original county shall remain and be the property of such original county; but, if the election is held for change in county boundaries, and any public building belonging to the county is located in the territory affected by the change of boundaries, the county acquiring the new territory shall pay the county from which such territory is taken the value of such public building.

(2) If any county is eliminated by the change in county boundaries, all public buildings and real property of the eliminated county and all liens for unpaid taxes become the property of the county acquiring the territory where the property is situated, and all public records and documents and all other property of every kind belonging to the eliminated county become the property of the county of which the largest area of the eliminated county becomes a part.