Oregon Revised Statutes Public Organizations for Community Service § 266.530

(1) The county treasurer shall register each bond issued pursuant to ORS 266.480 in a book kept for that purpose in the office of the county treasurer, noting the district, amount, date, time and place of payment, rate of interest and such other facts as may be deemed proper.

(2) The county treasurer shall cause the bonds to be delivered promptly to the purchasers upon payment therefor, and shall hold the proceeds of the sale of the bonds subject to the order of the district board to be used solely for the purpose for which the bonds were issued.

(3) When the bonds have been so executed, registered and delivered, their legality shall not be open to contest by the district or by any person or corporation for or on its behalf, for any reason whatever.