(a) Notwithstanding any other provision of law, the proceeds from any leases issued by the Secretary pursuant to section 47-2 of this title may be credited to the appropriation bearing the cost of administering (directly or by contract) the leases and of constructing, improving, and maintaining roads, utilities, buildings, and other facilities within the El Portal administrative site. In the administration of the leases, the Secretary may contract for the management of the leases and of the leased premises, subject to such terms and conditions, including the right of the Secretary to purchase and sell the unexpired terms of leases and subleases, as will protect the interests of the United States. The Secretary may also contract for the use by him of any improvements to leased property for purposes of the El Portal administrative site or for purposes of Yosemite National Park, and he may use the proceeds from any leases for the purpose of making payments under any such contract.

(b) The Secretary may at any time acquire the unexpired term of any lease or sublease issued or entered into pursuant to sections 47-2 to 47-6 of this title by purchase with funds available from the proceeds of leases, or with donated or appropriated funds, or by donation or exchange.