Rooks County (standard abbreviation: RO) is a county located in the U.S. state of Kansas. As of the 2010 census, the county population was 5,181. The county seat is Stockton, and the largest city is Plainville. The county was named for Private John C. Rooks of the 11th Kansas Infantry who died at the Battle of Prairie Grove near Fayetteville, Arkansas, during the Civil War.
According to the U.S. Census Bureau, the county has a total area of 895 square miles (2,320 km), of which 891 square miles (2,310 km) is land and 4.6 square miles (12 km) (0.5%) is water.
As of the census of 2000, there were 5,685 people, 2,362 households, and 1,556 families residing in the county. The population density was 6 people per square mile (2/km²). There were 2,758 housing units at an average density of 3 per square mile (1/km²). The racial makeup of the county was 97.13% White, 1.13% Black or African American, 0.42% Native American, 0.19% Asian, 0.02% Pacific Islander, 0.37% from other races, and 0.74% from two or more races. 1.06% of the population were Hispanic or Latino of any race.
There were 2,362 households out of which 29.10% had children under the age of 18 living with them, 55.40% were married couples living together, 7.20% had a female householder with no husband present, and 34.10% were non-families. 31.80% of all households were made up of individuals and 18.50% had someone living alone who was 65 years of age or older. The average household size was 2.32 and the average family size was 2.93.
In the county, the population was spread out with 25.20% under the age of 18, 6.40% from 18 to 24, 25.50% from 25 to 44, 21.50% from 45 to 64, and 21.50% who were 65 years of age or older. The median age was 40 years. For every 100 females there were 98.10 males. For every 100 females age 18 and over, there were 94.30 males.
The median income for a household in the county was $30,457, and the median income for a family was $36,931. Males had a median income of $26,794 versus $18,389 for females. The per capita income for the county was $15,588. About 7.30% of families and 9.80% of the population were below the poverty line, including 9.70% of those under age 18 and 7.40% of those age 65 or over.