ORS § 105.245
If it is alleged in the complaint and established by evidence, or if it appears by the evidence to the satisfaction of the court without an allegation in the complaint, that the property or any part of it is so situated that partition cannot be made without great prejudice to the owners, the court may order a sale of the property, and for that purpose may appoint one or more referees. Otherwise, upon the requisite proofs being made, it shall enter a judgment requiring a partition according to the respective rights of the parties, as ascertained by the court. The court shall appoint three referees to partition the property and shall designate the portion to remain undivided for the owners whose interest remain unknown or not ascertained.
ORS 105.245