Crook County is a county in the U.S. state of Oregon. As of the 2010 census, the population was 20,978. The county seat is Prineville. The county is named after George Crook, a U.S. Army officer who served in the American Civil War and various Indian Wars.
The county is located in the geographic center of Oregon. According to the U.S. Census Bureau, the county has a total area of 2,987 square miles (7,740 km), of which 2,979 square miles (7,720 km) is land and 8.2 square miles (21 km) (0.3%) is water. The largest body of water in Crook County is the Prineville Reservoir. The county has been reduced from its original size of 8,600 square miles (22,000 km) by the creation of Jefferson County in 1914 and Deschutes County in 1916. The present boundaries were established in 1927.
The oldest geological formation in Oregon is in the southeastern corner of Crook County, near its boundary with Grant County. This formation is an outcropping of Devonian limestone created from a larger reef when most of Oregon was covered by water.
As of the census of 2000, there were 19,182 people, 7,354 households, and 5,427 families residing in the county. The population density was 6 people per square mile (2/km²). There were 8,264 housing units at an average density of 3 per square mile (1/km²). The racial makeup of the county was 92.95% White, 0.04% Black or African American, 1.30% Native American, 0.43% Asian, 0.03% Pacific Islander, 3.81% from other races, and 1.43% from two or more races. 5.64% of the population were Hispanic or Latino of any race. 26.2% were of American, 14.8% German, 9.7% English and 8.9% Irish ancestry.
There were 7,354 households out of which 32.30% had children under the age of 18 living with them, 61.50% were married couples living together, 8.20% had a female householder with no husband present, and 26.20% were non-families. 21.30% of all households were made up of individuals and 9.50% had someone living alone who was 65 years of age or older. The average household size was 2.57 and the average family size was 2.96.
In the county, the population was spread out with 26.60% under the age of 18, 7.50% from 18 to 24, 25.50% from 25 to 44, 25.70% from 45 to 64, and 14.70% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 99.40 males. For every 100 females age 18 and over, there were 97.30 males.
The median income for a household in the county was $35,186, and the median income for a family was $40,746. Males had a median income of $32,166 versus $22,580 for females. The per capita income for the county was $16,899. About 8.10% of families and 11.30% of the population were below the poverty line, including 13.90% of those under age 18 and 8.10% of those age 65 or over.
As of the 2010 United States Census, there were 20,978 people, 8,558 households, and 6,025 families residing in the county. The population density was 7.0 inhabitants per square mile (2.7/km). There were 10,202 housing units at an average density of 3.4 per square mile (1.3/km). The racial makeup of the county was 92.7% white, 1.4% American Indian, 0.5% Asian, 0.2% black or African American, 0.1% Pacific islander, 3.2% from other races, and 2.0% from two or more races. Those of Hispanic or Latino origin made up 7.0% of the population. In terms of ancestry, 20.7% were German, 14.6% were English, 12.6% were Irish, and 6.2% were American.
Of the 8,558 households, 27.7% had children under the age of 18 living with them, 57.1% were married couples living together, 9.0% had a female householder with no husband present, 29.6% were non-families, and 24.1% of all households were made up of individuals. The average household size was 2.42 and the average family size was 2.84. The median age was 45.6 years.
The median income for a household in the county was $46,059 and the median income for a family was $52,477. Males had a median income of $41,375 versus $29,545 for females. The per capita income for the county was $22,275. About 10.6% of families and 14.0% of the population were below the poverty line, including 26.1% of those under age 18 and 4.0% of those age 65 or over.