2019 Sisseton Wahpeton Oyate Wacipi (SWO Powwow) Rate This Event Celebrate the 152nd Annual Sisseton Wahpeton Oyate Wacipi (SWO Powwow) on  July 5-7, 2019 at the SWO Ceremonial Grounds in Agency Village, South Dakota. The Sisseton Wahpeton Oyate Wacipi is the oldest powwows in South Dakota and the second oldest in the nation [read more]