Oregon Revised Statutes Agriculture § 561.265

(1) The State Department of Agriculture upon not less than three days' notice in writing is authorized to inspect and audit, during regular business hours, necessary and applicable books and records of any person required by law to report or pay fees or moneys to the department. Such inspection is for the purpose of determining whether proper fees have been paid.

(2) “Fees” as used in this section includes fees due the department by a person, each month, year, or other fixed time or period, the amount of which is based upon the quantity, volume, weight or other measurement of some article, product or commodity and such fees to be used by the department in carrying out or enforcing a law under its jurisdiction. “Fees” does not include a license fee, the exact amount of which is fixed by law.