16 USC 2 - National parks, reservations, and monuments; supervision

The director shall, under the direction of the Secretary of the Interior, have the supervision, management, and control of the several national parks and national monuments which on August 25, 1916, were under the jurisdiction of the Department of the Interior, and of the Hot Springs National Park in the State of Arkansas, and of such other national parks and reservations of like character as may be created by Congress. In the supervision, management, and control of national monuments contiguous to national forests the Secretary of Agriculture may cooperate with said National Park Service to such extent as may be requested by the Secretary of the Interior.