N.H. Rev. Stat. Ann. § 79-D:6

Any preservation easement acquired by the municipality pursuant to this chapter shall be for a minimum of 10 years. The easement terms shall include the method of assessment pursuant to RSA 79-D:7 and the terms of renewal pursuant to RSA 79-D:8, III. The local governing body shall provide for the recording of such easements with the register of deeds. Any costs of recording shall be the responsibility of the applicant.