The Island of Palawan is home to the largest nickel mines in the Philippines. Mining and related processing have taken place since the 1970's in this region. The village of Rio Tuba is in the Municipality of Bataraza, Province of Palawan. The Rio Tuba Nickel Mining Corporation (RTNMC) started open pit mining in 1975. It is currently the largest producer of lateritic nickel ore2 in the Philippines. Sumitomo Metal Mining Co. Ltd.