N.H. Rev. Stat. Ann. § 23:2

Any county as may be authorized by the county convention, may take land within its limits in fee by gift, purchase or right of eminent domain as a site for recreational activities; may prepare, equip and maintain it for such purposes; may conduct and promote thereon such activities; may charge, or authorize others to charge, reasonable admission and service fees; and may employ such supervisors, instructors and other officials as may be necessary.