Oregon Revised Statutes Evidence and Witnesses § 44.415

(1) Except as provided in subsection (2) of this section, a person is entitled to receive $30 for each day's attendance as a witness and mileage reimbursement at the rate of 25 cents a mile if the person is required to travel from a place within or outside this state in order to perform duties as a witness. Total mileage reimbursement shall not exceed the necessary cost of transportation on reasonably available common carriers.

(2) In any criminal proceeding, any proceeding prosecuted by a public body or any proceeding where a public body is a party, a person is entitled to receive $5 for each day's attendance as a witness and mileage reimbursement at the rate of eight cents a mile if the person is required to travel from a place within or outside this state in order to perform duties as a witness. Total mileage reimbursement shall not exceed the necessary cost of transportation on reasonably available common carriers.

(3) As used in this section, “public body” means any state, city, county, school district, other political subdivision, municipal corporation, public corporation and any instrumentality thereof.