When any such premises is posted as provided in Sections 9.34.010 through 9.34.080, it is unlawful for any person to go upon or to remain upon any place within the posted boundary of any such premises, or to enter or to remain in any such posted structure, without having upon his or her person the express written consent of the person, firm, corporation, department or agency lawfully in possession or control thereof. (Prior code § 10.45.040)