S.D. Codified Laws § 49-34-7
Every corporation organized under chapter 49-33 may build, maintain, and operate branch or spur tracks, electric light or power lines from its main line or any branch thereof to and upon the grounds of any mill, elevator, storehouse, warehouse, or manufacturing establishment with tracks, switches, and such turnouts as may be convenient or necessary, and may acquire its right-of-way for such spur tracks, electric light or power lines by grant, purchase, or condemnation; provided that the provisions of § 49-34-6 shall not apply to nor affect the provisions of this section if the branches and spur tracks, electric light or power lines herein mentioned do not exceed two miles in length from the line of such railroad, electric or power line.
SDCL 49-34-7