S.D. Codified Laws § 32-17-14
Every truck, truck tractor, bus with a capacity of ten or more passengers, trailer, semitrailer, and pole trailer having a width at any part in excess of eighty inches shall be equipped with four clearance lamps. Two of such lamps shall be located at the extreme right and left sides of the front of such vehicle, and displaying an amber light visible from a distance of five hundred feet to the front of the vehicle, and the remaining two lamps located at the extreme right and left sides of the rear of the vehicle and displaying red lights visible from a distance of five hundred feet to the rear of the vehicle, which rear clearance lamps shall be in addition to the red lamps required in § 32-17-8. A violation of this section is a petty offense.
SDCL 32-17-14