N.H. Rev. Stat. Ann. § 215-C:54

If any person shall willfully or maliciously deface, destroy, remove, obstruct, alter or otherwise tamper with any trail sign, marker, posting, or other fixed monument along any trail or on anyone's property, upon conviction he or she shall be guilty of a misdemeanor. Further, said person shall be liable for full restitution for any damage incurred for which he or she is charged. The provisions of this section do not apply to persons who are authorized to relocate, remove or alter signs, markers, or postings.