The lead producing area of south east Missouri continues to mine, beneficiate and process over 95% of the primary lead produced in the U.S. Two mining companies (Doe Run and Asarco) remain active in the area, with five mills producing lead concentrates for two Missouri smelters, zinc concentrates for an Illinois refinery, and copper concentrates for export. This update provides plant data for the comminution, classification, flotation and dewatering processes currently in operation on the lead belt.