About 56,000 people live in St. Francois County (pronounced "Francis"), which was formed in 1821 from parts of Jefferson, Ste. Genevieve, and Washington counties, and named for the St. Francois River. The river is believed to have been named for St. Francois of Assisi, founder of the Franciscan Order.

The area is widely known for its long-ago iron mining and smelting, carried out in the area of Iron Mountain in the southwest corner of the county. Its lead production operations made St. Francois County a key player in the Civil War. The St. Louis Iron Mountain Railroad ran through the county, permitting rapid deployment of troops from St. Louis if necessary. Though the county was solidly Union, there were pockets of Confederate activity throughout the war.

The city of Farmington is the county seat. Other cities include Bonne Terre, Desloge, Leadington and Park Hills.

Like much of Missouri, St. Francois County has beautiful, natural places of retreat for the world weary, especially at St. Francois State Park: there’s the comforting wilderness of the Pike Run Hills; the three hiking trails (one allows equestrians) of Coonville Creek Wild Area; and the perfect place for launching canoes, the Big River, which forms the southern boundary of the park.
Other places of interest in St. Francois County:

• Buck Mountain -- a 120-acre area is best known for its natural granite formations.
• Mark Twain National Forest -- the only national forest in the state covers 1,487,009 acres.
• St. Francis River
• St. Joe State Park – this third largest state park has two lead -ore mill buildings, which have been designated as the Missouri Mines State Historic Site.