16 U.S. Code § 428h - Ascertaining and marking line of battle
It shall be lawful for the authorities of any State having troops engaged in the Battle of Fort Donelson to enter upon the lands and approaches of the Fort Donelson National Battlefield for the purpose of ascertaining and marking the lines of battle of troops engaged therein:
“Fort Donelson National Battlefield” substituted in text for “Fort Donelson National Military Park” in view of redesignation of Fort Donelson National Military Park as Fort Donelson National Battlefield by Pub. L. 86–738. See section 428n of this title.
Transfer of administrative functions of park, see note set out under section 428 of this title.