There are 5 US Post Offices in Iron County serving a total of 7,610 residents equating to 1,522 residents per post office. It's estimated that approximately 12,146 packages are handled across the 5 county post offices annually. Iron County is a county located in the Lead Belt region in the U.S. state of Missouri. As of the 2010 census, the population was 10,630. The largest city and county seat is Ironton. Iron County was officially organized on February 17, 1857, and was named after the abundance of iron ore found within its borders. 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 is home to a number of state parks and historical sites including Taum Sauk Mountain State Park, Elephant Rocks State Park and Fort Davidson State Historic Site as well as 96,047 acres (390 km2) of Mark Twain National Forest."