The authorities of any State which had troops engaged in the Battle of Kings Mountain may enter the Kings Mountain National Military Park for the purpose of ascertaining and marking the lines of battle of such troops, but before any such lines are permanently designated the position of the lines and the proposed methods of marking them by monuments, tablets, or otherwise shall be approved by the Secretary of the Interior. Any State organization or individual may, with the approval of the Secretary of the Interior, erect monuments or place tablets within such park.