O'Brien County, Iowa

O'Brien County is a located in the  of. As of, the population is 15,102. It is named for, a leader for Irish independence in 1848, and is the only O'Brien County in the United States. Its is.

Geography
According to the, the county has a total area of 1,485 (573 ). 1,484 km² (573 sq mi) of it is land and 0 km² (0 sq mi) of it (0.03%) is water.

Adjacent counties

 * (north)
 * (east)
 * (south)
 * (west)

Demographics
As of the of 2000, there were 15,102 people, 6,001 households, and 4,122 families residing in the county. The was 10/km² (26/sq mi). There were 6,509 housing units at an average density of 4/km² (11/sq mi). The racial makeup of the county was 98.05%, 0.34% or , 0.17% , 0.51% , 0.01% , 0.47% from , and 0.46% from two or more races. 1.77% of the population were or  of any race.

There were 6,001 households out of which 30.40% had children under the age of 18 living with them, 61.00% were living together, 4.90% had a female householder with no husband present, and 31.30% were non-families. 28.00% of all households were made up of individuals and 14.70% had someone living alone who was 65 years of age or older. The average household size was 2.42 and the average family size was 2.97.

In the county the population was spread out with 24.80% under the age of 18, 7.80% from 18 to 24, 24.10% from 25 to 44, 22.10% from 45 to 64, and 21.10% who were 65 years of age or older. The median age was 41 years. For every 100 females there were 95.80 males. For every 100 females age 18 and over, there were 92.40 males.

The median income for a household in the county was $35,758, and the median income for a family was $42,959. Males had a median income of $30,446 versus $20,391 for females. The for the county was $17,281. About 4.60% of families and 7.30% of the population were below the, including 7.70% of those under age 18 and 6.00% of those age 65 or over.

Cities and towns
43.08139°N, -95.62611°W