ORS § 34.320
The circuit court of the judicial district wherein the party is imprisoned or restrained, and, if vested with power to exercise judicial functions, the county court and county judge of the county wherein the party is imprisoned or restrained, shall have concurrent jurisdiction of proceedings by habeas corpus, and said courts and judges may issue, hear and decide all questions arising upon habeas corpus. If a plaintiff has filed a petition in a court with jurisdiction over the proceedings, and the plaintiff is thereafter transferred to a place that is outside of the jurisdiction of that court, the court shall transfer the proceedings to the circuit court for the judicial district in which the party is imprisoned or restrained. If the court in which the petition was filed determines that by reason of the plaintiff's transfer the claims of the plaintiff do not require immediate judicial scrutiny, or are otherwise subject to dismissal, the court shall dismiss the petition.
ORS 34.320