Yankton, South Dakota Yankton, South Dakota Yankton is a city in, and the county seat of, Yankton County, South Dakota, United States. The population was 14,454 at the 2010 census. Yankton is the principal city of the Yankton Micropolitan Statistical Area, which includes the entirety of Yankton County, and which had an estimated population of 22,662 as of July 1, 2017. Yankton was the first capital of Dakota Territory. It is named for the Yankton tribe of Nakota (Sioux) Native Americans; Yankton is derived from the Nakota word "I-hank-ton-wan" ("the end village"). Yankton is located on the Missouri River just downstream of the
Kamiakin (Native American leader) Rock Lake in Whitman County, Washington in 1864, where he lived until his death. Kamiakin was of mixed Nez Perce, Spokane and Yakama ancestry. His father Ki-yi-yah was the son of a Nez Perce father and a Spokane mother. His mother was Yakama. In 1825 Kamiakin married Sal-kow, also a Yakama, whose father "Te-i-as" and grandfather "Weowikt" were leaders in the tribe. Kamiakin later married Colestah, also a Yakama. In 1855 Isaac Stevens, the new Washington Territory governor, was anxious to extinguish claims to traditional lands by regional tribes and free up Native American land for sale to European Americans,