Lake County is a county in the U.S. state of South Dakota. As of the 2020 census, the population was 11,059. Its county seat is Madison. The county was formed in 1873.
History
Lake County, South Dakota, was inhabited by the Sisseton Sioux when explorers, including Joseph Nicollet and John C. Fremont, first mapped the region in 1838–39 and noted its numerous lakes. The 1851 Treaty of Mendota with the Santee Sioux and 1858 Yankton Treaty opened the area for American settlement. The terrain generally slopes to the south, although high points (ca. 1,814' ASL) are found on the north and south boundary lines and points between.
Lake County has a total area of , of which is land and (2.1%) is water.
Lakes
Source:
| align = right
2020 census
As of the 2020 census, there were 11,059 people, 4,576 households, and 2,804 families residing in the county. Of the residents, 22.0% were under the age of 18 and 19.7% were 65 years of age or older; the median age was 40.0 years. For every 100 females there were 109.5 males, and for every 100 females age 18 and over there were 108.8 males.
Of the 4,576 households, 25.1% had children under the age of 18 living with them and 20.4% had a female householder with no spouse or partner present. About 32.2% of all households were made up of individuals and 13.8% had someone living alone who was 65 years of age or older.
Politics
Lake County voters have voted for Republican Party candidates in 62 percent of national elections since 1964.
<!-- PresRow should be -->
Education
School districts include:
- Chester School District 39-1
- Colman-Egan School District 50-5
- Madison Central School District 39-2
- McCook Central School District 43-7
- Oldham-Ramona-Rutland School District 39-6
- Sioux Valley School District 05-5
The Oldham-Ramona School District 39-5 and Rutland School District 39-4, in the county,