18 U.S.C. § 1793
Trespass on Bureau of Prisons reservations and land
Whoever, without lawful authority or permission, goes upon a reservation, land, or a facility of the Bureau of Prisons shall be fined under this title or imprisoned not more than six months, or both.
(Added Pub. L. 99–646, § 64(a) , Nov. 10, 1986 , 100 Stat. 3614 ; amended Pub. L. 103–322, title XXXIII, § 330016(1)(G) , Sept. 13, 1994 , 108 Stat. 2147 .)