N.H. Rev. Stat. Ann. § 215-A:33

If any person shall wilfully 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 shall be guilty of a misdemeanor. Further, said person shall be liable for full restitution for any damage incurred for which he is charged. The provisions of this section do not apply to persons who are authorized to relocate, remove or alter signs, markers or postings.