Oregon Revised Statutes Elections § 260.055

(1) Each candidate, other than a candidate for political party office, the treasurer of each political committee and the treasurer of each petition committee shall keep detailed accounts. The accounts shall be current as of not later than the seventh calendar day after the date of receiving a contribution or making an expenditure with respect to all contributions received and all expenditures made by or on behalf of the candidate or committee that are required to be reported under ORS 260.057, 260.076 or 260.078. Subject to ORS 260.085, the accounts shall list all information required to be reported under ORS 260.083.

(2) Accounts kept by a candidate or the treasurer of a political committee may be inspected under reasonable circumstances at any time before the election to which the accounts refer or during the period specified for retention of the accounts under subsection (3) of this section by any opposing candidate or the treasurer of any political committee for the same electoral contest. The right of inspection may be enforced by writ of mandamus issued by any court of competent jurisdiction. The treasurers of political committees supporting a candidate may be joined with the candidate as defendants in a mandamus proceeding.

(3) Accounts kept by a candidate or treasurer shall be preserved by the candidate or treasurer for at least two years after the date the statement of the contribution or expenditure is filed under ORS 260.057.