According to the U.S. Census Bureau, the county has a total area of 552 square miles (1,430 km2), of which 550 square miles (1,400 km2) is land and 1.8 square miles (4.7 km2) (0.3%) is water.[8]
As of the census[16] of 2000, there were 10,697 people, 4,197 households, and 2,963 families residing in the county. The population density was 7/km2 (18/sq mi). There were 4,907 housing units at an average density of 3/km2 (7.8/sq mi). 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.
Religion
According to the Association of Religion Data Archives County Membership Report (2000), Iron County is a part of the Bible Belt with evangelical Protestantism being the majority religion. The most predominant denominations among residents in Iron County who adhere to a religion are Southern Baptists (56.62%), Methodists (10.60%), and Roman Catholics (7.82%).
Historically, Iron County has been one of the most reliably Democratic counties in Missouri. Located in the Lead Belt region of the state, mining has been important to the county's economy. It was one of only three predominantly rural counties in Missouri to vote for Barack Obama in 2008 (nearby Washington and Ste. Genevieve counties being the other two). Like much of the rest of the state's rural areas, the county saw a rapid rightward swing starting in 2000, when George W. Bush became the first Republican since 1984 (and the second since 1972) to carry it, after Bill Clinton had carried it in 1996 by over twenty points. Apart from the interruption in 2008, the Republican vote share has, as of 2020, grown in every subsequent election. At the local and state levels, however, Iron County still remains quite Democratic. At the same time Romney won Iron County by 15 points in 2012, all Democratic statewide candidates Jay Nixon (Governor), Claire McCaskill (U.S. Senator), Jason Kander (Secretary of State), Chris Koster (Attorney General), and Clint Zweifel (State Treasurer) carried Iron County by healthy margins; Peter Kinder (Lieutenant Governor) was the only other statewide Republican to win Iron County alongside Romney, and even then, the margin of victory was smaller than in most other rural counties.
Like most rural areas throughout Southeast Missouri, voters in Iron County generally adhere to socially and culturally conservative principles but are more moderate or populist on economic issues. In 2004, Missourians voted on a constitutional amendment to define marriage as the union between a man and a woman—it overwhelmingly passed Iron County with 80.90 percent of the vote. The initiative passed the state with 71 percent of support from voters as Missouri became the first state to ban same-sex marriage. In 2006, Missourians voted on a constitutional amendment to fund and legalize embryonic stem cell research in the state—it failed in Iron County with 56.03 percent voting against the measure. The initiative narrowly passed the state with 51 percent of support from voters as Missouri became one of the first states in the nation to approve embryonic stem cell research. Despite Iron County's longstanding tradition of supporting socially conservative platforms, voters in the county have a penchant for advancing populist causes like increasing the minimum wage. In 2006, Missourians voted on a proposition (Proposition B) to increase the minimum wage in the state to $6.50 an hour—it passed Iron County with 78.25 percent of the vote. The proposition strongly passed every single county in Missouri with 75.94 percent voting in favor as the minimum wage was increased to $6.50 an hour in the state. During the same election, voters in five other states also strongly approved increases in the minimum wage.
In the 2008 Missouri Presidential Preference Primary, voters in Iron County from both political parties supported candidates who finished in second place in the state at large and nationally. Former U.S. SenatorHillary Clinton (D-New York) received more votes, a total of 1,180, than any candidate from either party in Iron County during the 2008 Missouri Presidential Primaries. She also received more votes altogether than the total number of votes cast in the entire Republican Primary in Iron County.
Education
Of adults 25 years of age and older in Iron County, 65.2% possesses a high school diploma or higher while 8.4% holds a bachelor's degree or higher as their highest educational attainment.