Iron County includes the 6-mile (9.7 km)-long, 2-mile (3.2 km)-wide Arcadia Valley, the site of Pilot Knob, Ironton, and Arcadia, communities established by immigrants in the 19th Century. The valley is surrounded by the Saint Francois Mountains of the Ozarks Plateau. Iron County is also home to dozens of mountains, including the 1,772-foot (540 m) Taum Sauk Mountain, the highest point in Missouri.
The county also includes Taum Sauk Mountain State Park and 96,047 acres (390 km) of Mark Twain National Forest.
As of the census of 2000, there were 10,697 people, 4,197 households, and 2,963 families residing in the county. The population density was 7/km² (19/mi²). There were 4,907 housing units at an average density of 3/km² (9/mi²). The racial makeup of the county was 96.74% White, 1.56% Black or African American, 0.34% Native American, 0.09% Asian, 0.22% from other races, and 1.05% from two or more races. Approximately 0.58% of the population were Hispanic or Latino of any race.
There were 4,197 households out of which 32.00% had children under the age of 18 living with them, 56.80% were married couples living together, 9.40% had a female householder with no husband present, and 29.40% were non-families. 25.80% of all households were made up of individuals and 11.40% had someone living alone who was 65 years of age or older. The average household size was 2.46 and the average family size was 2.94.
In the county the population was spread out with 25.00% under the age of 18, 7.80% from 18 to 24, 25.30% from 25 to 44, 24.80% from 45 to 64, and 17.10% who were 65 years of age or older. The median age was 40 years. For every 100 females there were 94.80 males. For every 100 females age 18 and over, there were 90.80 males.
The median income for a household in the county was $31,276, and the median income for a family was $38,037. Males had a median income of $28,603 versus $16,615 for females. The per capita income for the county was $16,717. About 13.80% of families and 19.00% of the population were below the poverty line, including 27.60% of those under age 18 and 13.20% of those age 65 or over.