SDCL § 61-1-6: Employer subject to coverage by addition of another employing unit.

As used in this title, the term, employer, includes any individual, group of individuals or employing unit which acquired the organization, trade, or business, or substantially all of the assets thereof, of another employing unit and which, if treated as a single unit with such other employing unit would be an employer under § 61-1-4.