SDCL § 12-4-38: County auditor's file is official record in event of discrepancy.

The statewide voter registration file maintained by the secretary of state shall be considered a duplicate file of the official voter registration records held in each county office. If there is any discrepancy between the statewide voter registration file maintained by the secretary of state and the master registration file maintained by the county auditor, the master registration file maintained by the county auditor is the official file. However, for federal elections the statewide file shall be the official voter registration file. Upon request from the secretary of state, each county auditor shall transmit the county's entire voter file to the state voter registration file.