S.D. Codified Laws § 9-45-18
When two or more railroad companies own or operate separate lines of track to be crossed by any viaduct, the proportion of such viaduct and the approaches thereto to be constructed by each, or the cost to be borne by each, shall be determined by the governing body. Any railroad company shall proceed within the time and in the manner required by the governing body to construct, reconstruct, or repair any viaduct as required. It is a petty offense for any railroad company to neglect to perform such duty, and each day such company shall neglect to perform such duty shall constitute a separate offense.
Any such company may be compelled by mandamus or other appropriate proceeding to construct, reconstruct, or repair any viaduct so required.
SDCL 9-45-18