S.D. Codified Laws § 12-20-31
The officer in charge of an election may destroy voted ballots and pollbooks from a nonfederal election sixty days following the election at which such ballots were voted. However, they may not be destroyed if any recount or contest of such election is pending. The officer in charge of an election may destroy voted ballots, pollbooks and all other election material relating to a federal election twenty-two months after the election at which the ballots were voted. For the purpose of this section, a federal election is any election to nominate or elect persons to the United States Congress or other national elected position, including national issues or questions. If a ballot is used for a federal election and a state or local election, the ballots and all other election material shall be maintained for twenty-two months. All federal election material may be removed from the ballot box if it is maintained in such a manner as to guarantee the safety and integrity of such material.
SDCL 12-20-31