Yankton County, South Dakota
Yankton County is a county in the U.S. state of South Dakota. As of the 2020 census, the population was 23,310. Its county seat is Yankton. Yankton County comprises the Yankton, SD Micropolitan Statistical Area. Geography Yankton County lies on the south side of South Dakota. Its south boundary line abuts the north boundary line of the state of Nebraska (across the Missouri River). The Missouri flows eastward along the county's south border. The James River flows south-southeastward through the west central portion of the county, discharging into the Missouri near the midpoint of the county's south line. The county terrain consists of rolling hills, carved by creeks and drainages, hosting several lakes and ponds. The area is devoted to agriculture. The terrain slopes to the south and the east. Its highest point is ASL, on the eastern portion of its north boundary line. The county has a total area of , of which is land and (2.1%) is water. Lewis & Clark Lake, a popular regional tourist and recreational destination is found in the southwestern part of the county. Major highways U.S. Highway 81 South Dakota Highway 46 South Dakota Highway 50 South Dakota Highway 52 South Dakota Highway