; (B) the designation of new units of special airspace over the wilderness areas or wilderness additions designated by subsection (a); or (C) the use or establishment of military flight training routes over wilderness areas or wilderness additions designated by subsection (a). (7) Horses Nothing in this title precludes horseback riding in, or the entry of recreational or commercial saddle or pack stock into, an area designated as a wilderness area or wilderness addition by subsection (a)— (A) in accordance with section 4(d)(5) of the Wilderness Act ( 16 U.S.C. 1133(d)(5) ); and (B) subject to any terms and conditions determined to be necessary by the Secretary. (8) Law enforcement Nothing in this title precludes law enforcement and drug interdiction efforts within the wilderness areas and wilderness additions designated by subsection (a) in accordance with the Wilderness Act ( 16 U.S.C. 1131 et seq.). (9) Withdrawal Subject to valid existing rights, the wilderness areas and wilderness additions designated by subsection (a) are withdrawn from— (A) all forms of entry, appropriation, and disposal under the public land laws; (B) location, entry, and patent under the mining laws; and (C) operation of the mineral materials and geothermal leasing laws. (10) Incorporation of acquired land and interests Any land within the boundary of a wilderness area or wilderness addition designated by subsection (a) that is acquired by the United States shall— (A) become part of the wilderness area in which the land is located