N.H. Rev. Stat. § 215-A:17
The commissioner of the department of natural and cultural resources may designate employees of the bureau as forest and park patrol officers. The chief supervisor appointed under RSA 215-A:16, II and the forest and park patrol officers shall have the authority of peace officers as defined under RSA 594:1 to enforce the provisions of this chapter anywhere in the state and all rules of the department of natural and cultural resources on lands owned by, leased to or under control of the department of natural and cultural resources. Forest and park patrol officers shall also have authority as peace officers under RSA 594:1 to enforce laws dealing with trespass, litter, breaking and entering, larceny and vandalism on lands owned by, leased to or otherwise being used by the state in connection with official recreational or OHRV trails.
RSA 215-A:17
1981, 538:3. 2005, 210:20, eff. July 1, 2006. 2017, 156:14, I, eff. July 1, 2017.