S.D. Codified Laws § 41-13A-7
A law enforcement officer may only stop a conveyance at a location other than an inspection station established under this chapter, and may only inspect the conveyance for the presence of organisms, or organic material that may harbor aquatic invasive species if the conveyance is visibly transporting organisms or organic material, including animals, plants, or mud, or the law enforcement officer otherwise reasonably believes, based on articulable facts, that the conveyance is in violation of any of the provisions of §§ 41-13A-2 through 41-13A-4. If a law enforcement officer conducts an inspection of a conveyance and finds the presence of organisms, organic material, or water, that may harbor aquatic invasive species, a law enforcement officer may do the following:
SDCL 41-13A-7