S.D. Codified Laws § 32-17-8.1
Except for a vehicle equipped with a slow-moving vehicle emblem in compliance with §§ 32-15-20 and 32-15-21, each motor vehicle, trailer, semitrailer, and pole trailer shall be equipped with at least two stop lamps with at least one on each side. The side stop lamps shall be mounted on the same level and as widely spaced laterally as practicable. However, each motor vehicle, trailer, semitrailer, and pole trailer manufactured and assembled before July 1, 1973, and each motorcycle and motor-driven cycle shall be equipped with at least one stop lamp. A stop lamp shall be mounted on the rear of the vehicle at a height of no more than seventy inches nor less than fifteen inches. Each stop lamp shall display a red light visible from a distance of not less than three hundred feet to the rear in normal sunlight, except for a moped, which shall be visible from a distance of not less than one hundred fifty feet. Each stop lamp shall be actuated upon application of the brake which may be incorporated with one or more rear lamps. A violation of this section is a petty offense.
SDCL 32-17-8.1