Flags on OHV are a requirement for riding in the Imperial Sand Dunes 43 CFR 8365.1-6 states safety flags are required on all vehicles in the Imperial Sand Dunes Recreation Area (Including 2 wheelers like dirtbikes. ) All vehicles shall be equipped with a whip mast and a 6×12 inch red/orange flag. Flags may be of pennant, triangle, square, or rectangular shape. Masts must be securely mounted on the vehicle and extend 8 feet from the ground to the mast tip. Safety flags must be attached within 10 inches of the tip of the whip mast with club or other flags mounted below safety flag or on another whip.