N.H. Rev. Stat. Ann. § 259:108

"Tractor" shall mean: any self-propelled vehicle designed or used for agricultural purposes or as a traveling power plant or for drawing other vehicles, but having no provision for carrying a load other than attached implements such as snowplows, tool boxes, or bucket loaders, but shall not include vehicles used for recreational purposes or agricultural/industrial utility vehicles as defined in RSA 259:2-a.