What a trail means in legal terms.
Definitions can be really broad or quite specific.
The National Recreation Trails Program defines a trail as, "A trail is a travel way established either through construction or use and is passable by at least one or more of the following, including but not limited to: foot traffic, stock, watercraft, bicycles, in-line skates, wheelchairs, cross-country skis, off-road recreation vehicles such as motorcycles, snowmobiles, ATVs and 4-wheel drive vehicles."
The Recreational Trails Program legislative definition of a trail is:
23 U.S.C. 206:
§ 206. Recreational trails program
(a) DEFINITIONS.—In this section, the following definitions apply:
(1) MOTORIZED RECREATION.—The term ‘motorized recreation’ means off-road recreation using any motor-powered vehicle, except for a motorized wheelchair.
(2) RECREATIONAL TRAIL.—The term ‘recreational trail’ means a thoroughfare or track across land or snow, used for recreational purposes such as—
(A) pedestrian activities, including wheelchair use;
(B) skating or skateboarding;
(C) equestrian activities, including carriage driving;
(D) nonmotorized snow trail activities, including skiing;
(E) bicycling or use of other human-powered vehicles;
(F) aquatic or water activities; and
(G) motorized vehicular activities, including all-terrain vehicle riding, motorcycling, snowmobiling, use of off-road light trucks, or use of other off-road motorized vehicles.