S.D. Codified Laws § 32-17-8
Every motor vehicle, trailer, semitrailer, and pole trailer, except as otherwise provided in this section, and any other vehicle which is being drawn at the end of a combination of vehicles shall be equipped with at least two tail lamps mounted on the rear, which when lighted as required in § 32-17-4 shall emit a red light plainly visible from a distance of one thousand feet to the rear. However, motor vehicles, trailers, semitrailers, and pole trailers manufactured and assembled prior to July 1, 1973, shall have one tail lamp mounted on the left side of the rear which when lighted as required in § 32-17-4 shall emit a red light plainly visible from a distance of five hundred feet to the rear. Motorcycles and motor driven cycles, except mopeds as defined in § 32-20-1, shall have at least one tail lamp, which when lighted as required in § 32-17-4 shall emit a red light plainly visible from a distance of five hundred feet to the rear. Mopeds shall have at least one tail lamp which when lighted as required in § 32-17-4 shall emit a red light plainly visible from a distance of two hundred and fifty feet to the rear. Farm vehicles which are being drawn at the end of a train of vehicles may be equipped with two four-inch reflectors in lieu of lighted lamps as provided in this section so as to exhibit a red light plainly visible from a distance of five hundred feet to the rear. On a combination of vehicles, only the tail lamps on the rearmost vehicle need actually be seen from the distance specified. On vehicles with more than one tail lamp, the lamps shall be mounted on the same level and as widely spaced laterally as practicable. Every tail lamp upon every vehicle shall be located at a height of not more than seventy-two inches nor less than fifteen inches. A violation of this section is a petty offense.
SDCL 32-17-8