For the first time since 1916, every statewide South Dakota state office has a minor party or independent candidate on the general election ballot. See this newspaper story, which focuses on the Libertarian Party statewide nominating convention and, at the bottom, lists all the nominees for all the statewide offices.
There is no minor party candidate for Governor, Lieutenant Governor, U.S. Senate, or U.S. House, but there are independent candidates for all those offices except for U.S. House. The reason there are no minor party nominees for those four offices is that all parties must nominate by primary for those four offices (but not for the other statewide state offices). South Dakota makes it very difficult for a minor party member to get on his or her own primary’s ballot for statewide offce. They each need 250 signatures of party members; no other voters can sign. Typically qualified minor parties in South Dakota have 1,000 registered members or fewer, and it isn’t practical to get 250 signatures from such a small pool. No minor party candidate has managed to do it since 2006.
The Socialist Party had a complete slate for all the statewide state offices in 1916, but not since then. The Progressive Party in 1926, 1924, and 1914 covered most, but not all, of the statewide offices, as did the Prohibition Party in 1916 and 1914 (the Progressive Party of 1926 was a powerful party in South Dakota but was not associated with any national party that year).