N.H. Rev. Stat. Ann. § 106-N:14

Any person who enters or remains in a railroad station, upon the platform or grounds adjacent to a station, or upon any property of a railroad knowingly without license or privilege to do so, or a person who enters or remains upon or returns to said property in defiance of an order of a station agent or any police officer shall be guilty of criminal trespass as provided in RSA 635:2.