the Secretary may extend the existence of the Advisory Commission for a period of not more than 10 years beyond the date described in paragraph (1). (ii) Timing The Secretary shall make a determination to extend the existence of the Advisory Commission under clause (i) not later than 180 days before the date described in paragraph (1). 12. Savings provision Except as provided in section 4(e), nothing in this Act enlarges or diminishes the authority of any official at, or transfers the administration or management of, any National Park Service site or any partner site to the Recreation Area.