Lakes

One of Minnesota's nicknames is "Land of 10,000 Lakes", and it is speckled with bodies of water large and small. But four of the state's counties do not contain a natural lake; Rock County is one of them.^[9] Rock County did host a manmade lake from 1938 until 2014: a WPA work project constructed a small dam (the "Lower Dam") on Blue Mounds Creek in 1938, creating a small lake in Blue Mounds State Park. This continued until June 2014, when the dam was damaged by rain and floodwaters, allowing the pond to drain.^[10] In June 2016 the Minnesota Department of Natural Resources announced its decision not to rebuild the dam.^[11]

Major highways

Adjacent counties^[6]

Protected areas^[5]

• Blue Mounds State Park
• Northern Tallgrass Prairie National Wildlife Refuge (part)

2020 census

Note: the US Census treats Hispanic/Latino as an ethnic category. This table excludes Latinos from the racial categories and assigns them to a separate category. Hispanics/Latinos can be of any race.

2000 census

As of the census of 2000, there were 9,721 people, 3,843 households, and 2,705 families in the county. The population density was 20.2 per square mile (7.8/km²). There were 4,137 housing units at an average density of 8.58 per square mile (3.31/km²). The racial makeup of the county was 97.27% White, 0.53% Black or African American, 0.43% Native American, 0.62% Asian, 0.02% Pacific Islander, 0.53% from other races, and 0.59% from two or more races. 1.28% of the population were Hispanic or Latino of any race. 41.4% were of German, 23.8% Dutch and 16.5% Norwegian ancestry.

There were 3,843 households, out of which 31.30% had children under the age of 18 living with them, 62.10% were married couples living together, 5.50% had a female householder with no husband present, and 29.60% were non-families. 27.00% of all households were made up of individuals, and 15.70% had someone living alone who was 65 years of age or older. The average household size was 2.47 and the average family size was 3.01.

The county population contained 26.30% under the age of 18, 7.20% from 18 to 24, 24.10% from 25 to 44, 22.00% from 45 to 64, and 20.40% who were 65 years of age or older. The median age was 40 years. For every 100 females there were 97.60 males. For every 100 females age 18 and over, there were 93.00 males.

The median income for a household in the county was $38,102, and the median income for a family was $44,296. Males had a median income of $28,776 versus $22,166 for females. The per capita income for the county was $17,411. About 5.50% of families and 8.00% of the population were below the poverty line, including 8.10% of those under age 18 and 8.90% of those age 65 or over.

Cities

Unincorporated communities

• Ash Creek
• Kanaranzi
• Manley

Ghost towns

• Bruce
• Carnegie

Townships

National politics

Rock County traditionally votes Republican. In no presidential election since 1964 has it selected the Democratic candidate. Along with its northern neighbor Pipestone County, it was one of only two Minnesota counties Amy Klobuchar did not win in her 2012 Senate race.^[25]