Within the wilderness areas designated by this subchapter, the grazing of livestock, where established prior to
December 31, 1987, shall be permitted to continue subject to such reasonable regulations, policies, and practices as the Secretary deems necessary, as long as such regulations, policies, and practices fully conform with and implement the intent of Congress regarding grazing in such areas as such intent is expressed in the Wilderness Act [
16 U.S.C. 1131 et seq.] and
[section 108 of Public Law 96–560] (
16 U.S.C. 1133 note).