The mineral wealth of the region played an important role in the development of Estill County. The Shawnee mined lead in the area, and early settlers recognized the industrial potential of the region. The production of iron began in about 1810 and became one of the earliest industries. Evidence of the once-thriving iron industry can be found in the ruins of the Estill steam furnace, which operated from 1830 to 1874; the Cottage furnace; the Red River iron furnace; and the Fitchburg furnace. The iron industry declined after 1865 when iron deposits and timber to fire the furnaces were depleted, and innovations in the iron industry made charcoal furnaces obsolete.