Oregon Revised Statutes Revenue and Taxation § 319.920

(1) On a date determined by the Department of Transportation under ORS 319.910, the registered owner or lessee of a subject vehicle shall report the metered use by the subject vehicle and pay to the department the per-mile road usage charge due under ORS 319.885 for the reporting period.

(2) Unless a registered owner or lessee presents evidence in a manner approved by the department by rule that the subject vehicle has been driven outside this state, the department shall assume that all metered use reported represents miles driven by the subject vehicle on the highways in Oregon.