32 CFR 234.4 - Trespassing.
(a) Trespassing, entering, or remaining in or upon property not open to the public, except with the express invitation or consent of the person or persons having lawful control of the property, is prohibited. Failure to obey an order to leave under paragraph (b) of this section, or reentry upon property after being ordered to leave or not reenter under paragraph (b) of this section, is also prohibited.
(b) Any person who violates a Department of Defense rule or regulation may be ordered to leave the Pentagon Reservation by an authorized person. A violator's reentry may also be prohibited.