Chevron Corporation operates five coal and metal mines in the United States through its subsidiary, Chevron Mining that has a staff of more than 1,500 employees and provides coal and other minerals to customers around the world. Chevron Mining is the result of the merging between Pittsburg & Midway Mining Company and Molycorp. The company operates three coal mines that include McKinley, Kemmerer and the North River Mine. Chevron Mining also owns a 33 percent interest in Sumikin Molycorp, which manufactures rare earth compounds at its facilities in Japan. Its parent company Chevron Corporation is one of world's largest nongovernment energy companies. The parent company is engaged in every aspect of the oil and gas industry, including exploration and production; refining, marketing and transport; chemicals manufacturing and sales; and power generation.