S.D. Codified Laws § 10-28-19
Every railroad company shall keep on file, with the county auditor of each county through or into which its line or lines of railroad run, a map showing correctly the right-of-way, length of sidetracks outside the corporate limits of municipalities, depot grounds, yard room, gravel or sand beds, and lands for snow protection, and lands otherwise actually and necessarily used by it in the maintenance and operation of its railway at the date of filing such map showing lots or parts of lots and blocks in municipalities and the number of acres in each government subdivision, and it shall be the duty of the county auditor to provide for the exception from assessment by the director of equalization of all such right-of-way, depot grounds, yard room, gravel or sand beds, and lands for snow protection, or land otherwise actually and necessarily used in the operation of its railway.
SDCL 10-28-19