S.D. Codified Laws § 31-28-7
The public board or officer whose duty it is to repair or maintain any public highway shall erect and maintain at points in conformity with standard uniform traffic control practices on each side of the place at which a highway crosses an operational railway track or right-of-way, except within the limits of municipalities, a standard railroad advance warning sign. The sign shall be on the right-hand side of the highway approaching such crossing and at a distance from the crossing as the department or other controlling body shall direct. Any legally abandoned or nonoperational track which is crossed by a public highway and at which the crossing has been properly marked as a railway grade crossing may be marked with a supplemental sign, meeting uniform traffic control practices, to inform drivers of vehicles identified in § 32-29-5 that a stop is not required at that crossing. Failure to comply with the provisions of this section is a Class 1 misdemeanor.
SDCL 31-28-7