Map
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Location in the state of
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!style="background:#efefef;"| Area - Total - Land - Water
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According to the U.S. Census Bureau, the county has a total area of 1,062 km² (410 mi²). 1,055 km² (408 mi²) of it is land and 7 km² (3 mi²) of it (0.65%) is water.
As of the census2 of 2000, there were 20,578 people, 7,371 households, and 5,572 families residing in the county. The population density was 20/km² (50/mi²). There were 7,949 housing units at an average density of 8/km² (20/mi²). The racial makeup of the county was 90.25% White, 0.87% Native American, 0.85% Asian, 0.10% Black or African American, 0.03% Pacific Islander, 5.57% from other races, and 2.33% from two or more races. 11.92% of the population were Hispanic or Latino of any race.
There were 7,371 households out of which 37.70% had children under the age of 18 living with them, 62.00% were married couples living together, 9.30% had a female householder with no husband present, and 24.40% were non-families. 20.60% 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 2.78 and the average family size was 3.21.
In the county the population was spread out with 30.60% under the age of 18, 7.90% from 18 to 24, 26.60% from 25 to 44, 21.70% from 45 to 64, and 13.20% who were 65 years of age or older. The median age was 34 years. For every 100 females there were 98.30 males. For every 100 females age 18 and over, there were 94.80 males.
The median income for a household in the county was $33,046, and the median income for a family was $37,430. Males had a median income of $30,641 versus $21,421 for females. The per capita income for the county was $14,924. About 9.70% of families and 13.20% of the population were below the poverty line, including 16.70% of those under age 18 and 12.20% of those age 65 or over.
