Minnehaha County is a county on the eastern border of the state of South Dakota. As of the 2010 United States Census, the population was 169,468, making it the most populous county in South Dakota. Its county seat is Sioux Falls, the largest city in the state. The county was created in 1862 and organized in 1868. Its name was derived from the Sioux word Mnihaha, meaning “rapid water,” or “waterfall” (often also incorrectly translated as “laughing water”).
Minnehaha County lies on the east side of South Dakota. Its east boundary line abuts the west boundary line of the state of Minnesota as well as the north and west boundary lines of the state of Iowa. The Big Sioux River flows south-southeasterly through the east central part of the county. Its terrain consists of rolling hills, devoted to agriculture except around built-up areas, and dotted with lakes and ponds in its western portion. Its terrain generally slopes to the south, and in addition the east and west edges slope to the river valley through the center of the county. Its highest point is in the NW corner, at 1,752′ (534m) ASL.
Minnehaha County has a total area of 814 square miles (2,110 km), of which 807 square miles (2,090 km) is land and 6.7 square miles (17 km) (0.8%) is water.
As of the 2000 United States Census, there were 148,281 people, 57,996 households, and 37,581 families in the county. The population density was 183 people per square mile (71/km²). There were 60,237 housing units at an average density of 74 per square mile (29/km²). The racial makeup of the county was 93.03% White, 1.51% Black or African American, 1.85% Native American, 1.01% Asian, 0.05% Pacific Islander, 1.04% from other races, and 1.51% from two or more races. 2.15% of the population were Hispanic or Latino of any race.
There were 57,996 households out of which 33.80% had children under the age of 18 living with them, 51.80% were married couples living together, 9.50% had a female householder with no husband present, and 35.20% were non-families. 27.80% of all households were made up of individuals and 8.60% had someone living alone who was 65 years of age or older. The average household size was 2.46 and the average family size was 3.04.
The county population contained 26.20% under the age of 18, 10.80% from 18 to 24, 32.00% from 25 to 44, 20.00% from 45 to 64, and 11.00% who were 65 years of age or older. The median age was 34 years. For every 100 females, there were 98.10 males. For every 100 females age 18 and over, there were 95.40 males.
The median income for a household in the county was $42,566, and the median income for a family was $52,031. Males had a median income of $32,208 versus $24,691 for females. The per capita income for the county was $20,713. About 5.00% of families and 7.50% of the population were below the poverty line, including 8.90% of those under age 18 and 7.20% of those age 65 or over.
As of the 2010 United States Census, there were 169,468 people, 67,028 households, and 42,052 families in the county. The population density was 210.0 inhabitants per square mile (81.1/km). There were 71,557 housing units at an average density of 88.7 per square mile (34.2/km). The racial makeup of the county was 88.1% white, 3.8% black or African American, 2.5% American Indian, 1.5% Asian, 0.1% Pacific islander, 1.8% from other races, and 2.3% from two or more races. Those of Hispanic or Latino origin made up 4.1% of the population. In terms of ancestry, 43.8% were German, 17.7% were Norwegian, 11.6% were Irish, 6.8% were Dutch, 6.3% were English, and 3.2% were American.
Of the 67,028 households, 32.7% had children under the age of 18 living with them, 47.7% were married couples living together, 10.5% had a female householder with no husband present, 37.3% were non-families, and 29.3% of all households were made up of individuals. The average household size was 2.43 and the average family size was 3.03. The median age was 34.5 years.
The median income for a household in the county was $51,799 and the median income for a family was $64,645. Males had a median income of $40,187 versus $31,517 for females. The per capita income for the county was $26,392. About 6.9% of families and 9.7% of the population were below the poverty line, including 12.2% of those under age 18 and 7.6% of those age 65 or over.