ORS § 391.580
The principal, interest and premiums, if any, on any bonds issued by the Oregon Mass Transportation Financing Authority shall be secured solely by a pledge of the income, revenues and receipts out of which the same shall be made payable and may also be secured by and payable out of proceeds from the sale of the mass transit facility acquired or financed by the proceeds of such bonds. In addition, the district which is to lease or purchase the mass transit facilities financed out of the proceeds of any bonds issued by the authority may, by resolution of the district board, pledge all or any part of the revenues of the district derived from any taxes which the district is authorized to levy as security for the payment of the principal, interest and premiums, if any, on the bonds issued by the authority to finance such mass transit facilities. In the resolution of the district board pledging all or any part of its tax revenues as security for any bonds issued by the authority, the district may reserve the right to pledge from time to time on a parity basis all or any part of its tax revenues as security for any one or more series of bonds issued thereafter by the authority or the district, and in the event the right so reserved by the district is exercised all bonds secured by a pledge of such tax revenues shall be equally and ratably secured by such tax revenues without preference or priority of any kind of any bond or series of bonds secured thereby over any other bond or series of bonds secured thereby. A pledge of tax revenues by a district as a security for the payment of any bonds issued by the authority shall not be considered to be the incurring of bonded indebtedness by the district. Any pledge made pursuant to this section shall be valid and binding from and after the date of issuance of the bonds secured thereby and the income, revenues, receipts or taxes pledged shall be immediately subject to the lien of such pledge without the physical delivery thereof, the filing of any notice or any further act. The lien of any such pledge shall be valid and binding against all persons having claims of any kind against the pledgor whether in tort, contract or otherwise, irrespective of whether such persons have notice thereof. The resolution under which the bonds are authorized to be issued and any indenture executed as security for the bonds, may contain any agreements and provisions with respect to the maintenance of the properties covered thereby, the fixing and collection of rents for any portions leased by the authority to a district, the pledge of the agreement of the district to make such payments as shall be necessary to pay principal, interest and premiums, if any, on the bonds, the creation and maintenance of special funds from such revenues, and the rights and remedies available in the event of default, designation of a trustee, and any other provision the board shall deem advisable. Each pledge and agreement made for the benefit or security of any of the bonds of the authority shall continue effective until the principal, interest and premiums, if any, on the bonds for the benefit of which the same were made shall have been fully paid or provision for such payment duly made.
ORS 391.580