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 12,786 km² (4,937 mi²). 12,757 km² (4,925 mi²) of it is land and 29 km² (11 mi²) of it (0.23%) is water. The highest point in Idaho, Borah Peak (12,655 feet), is located in Custer County.
As of the census2 of 2000, there were 4,342 people, 1,770 households, and 1,196 families residing in the county. The population density was 0/km² (1/mi²). There were 2,983 housing units at an average density of 0/km² (1/mi²). The racial makeup of the county was 97.28% White, 0.55% Native American, 0.02% Asian, 0.02% Pacific Islander, 1.17% from other races, and 0.94% from two or more races. 4.21% of the population were Hispanic or Latino of any race.
There were 1,770 households out of which 29.90% had children under the age of 18 living with them, 60.10% were married couples living together, 4.40% had a female householder with no husband present, and 32.40% were non-families. 27.70% of all households were made up of individuals and 11.30% had someone living alone who was 65 years of age or older. The average household size was 2.41 and the average family size was 2.96.
In the county the population was spread out with 25.50% under the age of 18, 4.80% from 18 to 24, 25.90% from 25 to 44, 29.30% from 45 to 64, and 14.50% who were 65 years of age or older. The median age was 41 years. For every 100 females there were 104.50 males. For every 100 females age 18 and over, there were 106.80 males.
The median income for a household in the county was $32,174, and the median income for a family was $39,551. Males had a median income of $32,255 versus $21,463 for females. The per capita income for the county was $15,783. About 10.70% of families and 14.30% of the population were below the poverty line, including 16.70% of those under age 18 and 12.80% of those age 65 or over.
