ORS § 30.320
A suit or action may be maintained against any county and against the State of Oregon by and through and in the name of the appropriate state agency upon a contract made by the county in its corporate character, or made by such agency and within the scope of its authority; provided, however, that no suit or action may be maintained against any county or the State of Oregon upon a contract relating to the care and maintenance of an adult in custody or patient of any county or state institution. An action or suit may be maintained against any other public corporation mentioned in ORS 30.310 for an injury to the rights of the plaintiff arising from some act or omission of such other public corporation within the scope of its authority. An action may be maintained against any governmental unit mentioned in ORS 30.310 for liability in tort only as provided in ORS 30.260 to 30.300. An action or suit to quiet title may be maintained against any governmental unit mentioned in ORS 30.310.
ORS 30.320