SDCL § 25-1-8: Bigamous marriage void--Former spouse absent or believed dead.

A subsequent marriage contracted by any person during the life of a former husband or wife of such person with any person other than such former husband or wife, is null and void from the beginning, unless the former marriage has been annulled or dissolved, or unless such former husband or wife was absent and not known to such person to be living for the space of five successive years immediately preceding such subsequent marriage, or was generally reputed and was believed by such person to be dead at the time such subsequent marriage was contracted, in either of which cases the subsequent marriage is valid until its nullity is adjudged by a competent tribunal.