Notwithstanding the provisions of existing law and without regard to sections 3111 and 3112 of title 40, but within the limitations of cost otherwise applicable, appropriations of the Forest Service may be expended for the erection of buildings, lookout towers, and other structures on land owned by States, counties, municipalities, or other political subdivisions, corporations, or individuals: Provided, That prior to such erection there is obtained the right to use the land for the estimated life of or need for the structure, including the right to remove any such structure within a reasonable time after the termination of the right to use the land.