43 CFR §8351.1-1

1. (a)Motorized vehicle use. No one shall operate a motorized vehicle along a national scenic trail except:
   1. (1)When motorized vehicular use is necessary to meet emergencies involving health, safety, fire suppression, or law enforcement; or
   2. (2)Where the authorized officer determines that adjacent landowners and land users have a need for reasonable access to their lands, interests in lands, or timber rights; or
   3. (3)On roads that are designated segments of the National Scenic Trail System and are posted as open to motorized vehicles.
2. (b)Penalties. In accordance with section 7(i) of the National Trails System Act of 1968, as amended (16 U.S.C. 1246), anyone convicted of violating this regulation is subject to a fine not to exceed $500 and/or imprisonment not to exceed six months.