Freeport-McMoRan Inc., is engaged in mineral exploration and development; mining and milling of copper, gold, molybdenum and silver; as well as the smelting and refining of copper concentrates. The company conducts its operations primarily through its principal operating subsidiaries, PT Freeport Indonesia, Freeport-McMoRan Corporation and Atlantic Copper. PT Freeport Indonesia's principal asset is Papua, Indonesia-based Grasberg mine, which contains the world's largest copper and gold reserves. Freeport conducts its mining operations through four primary divisions - North America copper mines, South America mining, Indonesia mining and Molybdenum. In North America, Freeport operates open-pit copper mines in Arizona and New Mexico. The company also has molybdenum mines in Colorado. All of these operations are wholly owned by Freeport, except Morenci, which is under a joint venture with Freeport holding. In South America, the company has operating copper mines in Peru and in Chile.