Stockton Mine, on the Stockton Coal Field, is New Zealand's largest opencast mining operation. The entrance to the mine is at the former settlement of Stockton. The mine is operated by Solid Energy in a partnership agreement with Downer Australia. Solid Energy obtained the Stockton Coal Mining Licence (CML) in 1987 for a period of 40 years. The coal field is situated between 5 to 10 kilometres linear distance south west of Stockton. The southernmost part of the coal field is only 5km away from the historic mining town of Denniston.