To the extent that the Taxation Compact constitutes an agreement with an Indian Tribe related to land owned by an Indian Tribe, it is arguable that the validity of such Taxation Compact is dependent upon obtaining the approval of the Secretary of the Interior of the United States or his authorized representative pursuant to 25 U.S.C. sec. 81. Accordingly, as an additional condition precedent, prior to the close of the 1996 legislative session of the Colorado General Assembly, the parties must obtain the written approval of the Secretary of the Interior, or his authorized representative, of this Taxation Compact, or, alternatively, a written statement from such duly authorized official indicating that such written approval is not necessary or required under federal law.