SDCL § 32-3-21: Unnumbered vehicles not subject to titling--Titling by number other than vehicle identification number.

The department may not title or issue a license for the operation of any motor vehicle without a vehicle identification number, except, the department may authorize the titling of motor vehicles by a number other than the vehicle identification number and when so titled, the number shall be deemed the vehicle identification number whenever the term vehicle identification number is used in this chapter.