Every June 5, South Dakotans celebrate 605 Day. The unofficial “holiday” was dreamed up by the South Dakota Department of Tourism in 2016 as a way to engage residents and encourage them to share their pride for the state. South Dakota is one of only twelve states with a single area code (605), a number that has become synonymous with our culture, so choosing a date to show appreciation for this place we call home was a no-brainer: June 5 (6/05) it was!