Resident Population in Yankton County, SD was 23.51700 Thous. of Persons in January of 2023, according to the United States Federal Reserve. Historically, Resident Population in Yankton County, SD reached a record high of 23.51700 in January of 2023 and a record low of 18.40000 in January of 1974. Trading Economics provides the current actual value, an historical data chart and related indicators for Resident Population in Yankton County, SD - last updated from the United States Federal Reserve on May of 2024.