In 1989, the South Dakota legislature unanimously passed legislation proposed by Governor George S. Mickelson to proclaim 1990 as the "Year of Reconciliation" between Native Americans and whites, to change Columbus Day to Native American Day and to make Martin Luther King’s birthday into a state holiday. Since 1990, the second Monday in October has been celebrated as Native American Day in South Dakota (Source: SL 1990, ch 7, § 2). South Dakota is the only state to practice non-observance of the federal holiday of Columbus Day by recognizing Native American Day.
Native Americans’ Day is dedicated to the remembrance of the great Native American leaders who contributed so much to the history of this state.
Source: sd.gov
In 2017 Native American Day in South Dakota in USA falls on October 9.