Okla. Stat. tit. 62 § 658
Subject to the subsequent provisions of this section, there shall exist a statutory mortgage lien upon the lands, buildings, and/or facilities acquired, constructed, reconstructed, extended, equipped, or improved, in whole or in part, with the proceeds of revenue bonds issued under this act which shall exist in favor of the holders of the bonds and in favor of the holders of the coupons attached to said bonds, and said lands, buildings, and/or facilities shall remain subject to such statutory mortgage lien until payment in full of the principal of and interest on said revenue bonds. Anything herein to the contrary notwithstanding, the resolution and/or indenture referred to in Section 5 of this act may impose a foreclosable mortgage lien upon the lands, buildings, and/or facilities acquired, constructed, reconstructed, extended, equipped, or improved, in whole or in part, with the proceeds of revenue bonds issued under this act and the nature and extent of said mortgage lien may be controlled by the resolution or indenture including, without limitation, provisions pertaining to the release of all or part of the lands, buildings, and/or facilities from the mortgage lien and the priority of mortgage lien in the event of successive bond issues as authorized by Section 5 of this act. Subject to such terms, conditions, and restrictions as may be contained in the resolution or indenture authorizing and/or securing the said bonds, any holder of bonds issued under the provisions of this act, or of any coupon attached thereto, may, either at law or in equity, enforce the mortgage lien and may, by proper suit, compel the performance of the duties of the officials of the issuing trustees set forth in this act and set forth in any resolution and/or indenture authorizing and/or securing the said bonds.
Okla. Stat. tit. 62, § 658