Oregon Revised Statutes Revenue and Taxation § 319.790

(1) Any user or seller against whom an assessment is made under ORS 319.760 and 319.780 may petition for a reassessment within 30 days after service of notice of the assessment. If a petition is not filed within the 30-day period, the amount of the assessment becomes conclusive.

(2) If a petition for reassessment is filed within the 30-day period the Department of Transportation shall reconsider the assessment and, if requested in the petition, shall grant the user or seller an oral hearing and give the user or seller 10 days' notice of the time and place thereof. The department may continue the hearing from time to time. The department shall serve on the petitioner notice of its finding upon reassessment. If the finding is that a tax or penalty is delinquent, the petitioner shall pay to the department, within 30 days after notice is served, all the tax or penalty found to be delinquent.

(3) Notice required by this section shall be served in the manner prescribed by ORS 319.760 (3).