Oregon Constitution Art. XI-E § 1

The credit of the state may be loaned and indebtedness incurred in an amount which shall not exceed at any one time 3/16 of 1 percent of the true cash value of all the property in the state taxed on an ad valorem basis, to provide funds for forest rehabilitation and reforestation and for the acquisition, management, and development of lands for such purposes. So long as any such indebtedness shall remain outstanding, the funds derived from the sale, exchange, or use of said lands, and from the disposal of products therefrom, shall be applied only in the liquidation of such indebtedness. Bonds or other obligations issued pursuant hereto may be renewed or refunded. An ad valorem tax shall be levied annually upon all the property in the state of Oregon taxed on an ad valorem basis, in sufficient amount to provide for the payment of such indebtedness and the interest thereon. The legislative assembly may provide other revenues to supplement or replace the said tax levies. The legislature shall enact legislation to carry out the provisions hereof. This amendment shall supersede all constitutional provisions in conflict herewith.