Subject to valid rights in existence on October 21, 1999, the wilderness areas designated under this subchapter shall be administered by the Secretary in accordance with the Wilderness Act (
16 U.S.C.
1131 et seq.) except that any reference in such provisions to the effective date of the Wilderness Act shall be deemed to be a reference to the effective date of this subchapter and any reference to the Secretary of Agriculture shall be deemed to be a reference to the Secretary of the Interior.