S.D. Codified Laws § 12-16-17
The county auditor shall provide official and sample ballots to each precinct in the county. The quantity provided for a primary election shall be at least ten percent more than the number of votes cast for the gubernatorial candidate of the respective parties in the preceding gubernatorial primary election. The quantity provided for a general election shall be at least ten percent more than the number of votes cast for all candidates for Governor as shown by the returns of the last preceding gubernatorial election. The county auditor shall also provide and retain in that office an ample supply of all official ballots, and if at any time before or during an election, an additional supply for any precinct shall be requested by the precinct superintendent, the county auditor shall immediately cause to be delivered, to the precinct superintendent, a supply of extra official ballots. If the supply of official ballots has been completely exhausted, the county auditor may make emergency substitution by delivering or authorizing the use of sample ballots or photocopies of the official ballot. The election board shall account for any sample ballots or photocopies authorized to be used.
SDCL 12-16-17