Antimony ore was discovered in southwest Arkansas shortly after the Civil War.  Ore was mined until 1947, not because the mines played out but because the veins were narrow, sinuous and hard to follow.  The mines were often entered by vertical mine shaft and these were hard to keep from filling with water.  The area is in Sevier County near the small towns of King and Gillham.  Above is an old map of the area from a University of Arkansas Master’s Thesis entitled Geochemistry, Geothermometry and Mineralogy of Copper, Lead, Zinc and Antimony Deposits of Sevier County, Arkansas.  http://www.ericwilder.com   http://energyissues.blogharbor.com