South Dakota Attorney General Marty Jackley says his office is treating the U.S. Supreme Court's ruling as effective immediately, but says it's up to county officials whether to issue licenses right away.
Jackley says some local officials may need time to implement it.
Each county's register of deeds is responsible for issuing marriage licenses in South Dakota. Jackley says larger counties might need more time than smaller ones before they can begin issuing licenses.
Jackley says he believes South Dakota residents should define marriage and not the federal government. However, he says, the five Supreme Court justices who ruled in favor of same-sex marriages "have now determined neither the states nor our citizens have the right or the ability to define marriage."
(The Associated Press contributed to this report.)