off-road vehicle
(3) The term “off-road vehicle” means any motorized vehicle designed for, or capable of, cross-country travel on or immediately over land, water, sand, snow, ice, marsh, swampland, or other natural terrain; but such term does not include— (A) any registered motorboat at the option of each State; (B) any military, fire, emergency, or law enforcement vehicle when used for emergency purposes; and (C) any vehicle the use of which is expressly authorized by the Secretary of the Interior or the Secretary of Agriculture under a permit, lease, license, or contract.