36 C.F.R. § 1004.10
Travel on Presidio Trust roads and designated routes
(a) Operating a motor vehicle is prohibited except on Presidio Trust roads and in parking areas.
(b) The following are prohibited:
(1) Operating a motor vehicle not equipped with pneumatic tires, except that a track-laying motor vehicle or a motor vehicle equipped with a similar traction device may be operated on a route designated for these vehicles by the Board.
(2) Operating a motor vehicle in a manner that causes unreasonable damage to the surface of a Presidio Trust road or route.