Valles Mines is an unincorporated community in southern Jefferson County, Missouri, United States and Northern St. Francois County. It is located about seven miles south of De Soto and is less than a mile from U.S. Route 67. It is in the St. Louis Metropolitan Area.A post office called Valles Mines was established in 1826. The community is named after François Vallé, who established lead mines there in the 18th century.