S.D. Codified Laws § 38-24A-14
To effectuate the purposes of this chapter, the secretary of agriculture and natural resources may, with a search warrant or the consent of the owner, make reasonable inspection of any property in this state. The secretary may, without a search warrant, with or without the assistance of any law enforcement agency, stop and inspect, in a reasonable manner, any means of conveyance moving within this state upon probable cause to believe it contains or carries any pest, host, or other article subject to the provisions of this chapter, and may make any other reasonable inspection of any premises or means of conveyance for which no search warrant is required. The secretary may, if he believes that a pest exists, investigate the suspected premises after giving written notice. Such notice is considered given if it is given to the owner or person in charge of the premises by personal service at least one day before entry, or if it is mailed by certified mail addressed to the last known address of the owner at least five days before entry.
SDCL 38-24A-14