South Dakota Codified Laws
Chapter 46E - Excise Tax On Farm Machinery, Farm Attachment Units,
Section 10-46E-4 - Farm machinery defined.

10-46E-4. Farm machinery defined.
For purposes of this chapter, farm machinery, includes all-terrain vehicles of three or more wheels used exclusively by the purchaser for agricultural purposes on agricultural land. The purchaser shall sign and deliver to the seller a statement that the all-terrain vehicle will be used exclusively for agricultural purposes.

Source: SL 2006, ch 58, ยง4.