Oregon Revised Statutes Public Lands § 275.190

(1) Sales made under ORS 275.110 to 275.250 must be to the highest and best bidder:

(2) In advertising for bids, the county shall state whether the sale will be made for cash or by purchase agreement. If by a purchase agreement that allows for deferred payments, the county shall also state the term and the rate of interest to which the county will agree.

(3) The purchaser shall have the possession of, and the income from the premises so long as the purchaser is not in default in the performance of the purchase agreement with the county, but shall forfeit the purchaser's rights under the agreement and to all payments made pursuant thereto if the purchaser fails to pay the purchase price or any part of the purchase price, principal or interest, or to pay, before delinquency, the taxes thereafter levied against the premises, or commits or suffers any strip or waste of or on the premises, or violates any other reasonable provision of the purchase agreement that the governing body of the county may see fit to require. The purchaser shall have the privilege of prepayment without penalty. The provisions of this subsection must be incorporated in the purchase agreement.