Cliffs Natural Resources Inc. is a mining and natural resources company. The Company is a supplier of iron ore pellets to the North American steel industry from its mines and pellet plants located in Michigan and Minnesota. The Company's segments include U.S. Iron Ore and Asia Pacific Iron Ore. The Company is a producer of iron ore pellets, primarily selling production from U.S. Iron Ore to integrated steel companies in the United States, Canada and Mexico. Its Asia Pacific Iron Ore operations are located in Western Australia and consist of its Koolyanobbing operation. The Koolyanobbing operations serve the Asian iron ore markets with direct-shipped fines and lump ore. In addition, the Company operates an iron ore mining complex in Western Australia. In the United States, the Company owned four operational iron ore mines and one indefinitely idled mine, as of December 31, 2016. As of December 31, 2016, it operated four iron ore mines located in Michigan and Minnesota.