The Ranger Uranium Mine was a uranium mine in the Northern Territory of Australia. The site is surrounded by, but separate from Kakadu National Park, 230 km east of Darwin. The orebody was discovered in late 1969, and the mine commenced operation in 1980, reaching full production of uranium oxide in 1981 and ceased stockpile processing on 8 January 2021. Mining activities had ceased in 2012. It is owned and operated by Energy Resources of Australia (ERA), a public company 86.33% owned by Rio Tinto Group, the remainder held by the public. Uranium mined at Ranger was sold for use in nuclear power stations in Japan, South Korea, China, UK, France, Germany, Spain, Sweden and the United States. The original Ranger 1 orebody was mined out by the end of 1995, although some ore remained stockpiled. A second orebody, Ranger 3, began mining in 1997. Both were open-pit mines. Mining finished at Ranger in late 2012 and the mine plant processed stockpiled ore until January 2021. ERA has tenure and access to the site, principally for rehabilitation activities, until 8 January 2026. Discovery The Ranger uranium orebody, the richest in the southern hemisphere, was discovered in late 1969, when an aerial radiometric survey conducted by Geophysical Resources Development Co., a company based in Sydney, on contract to Noranda Aluminum, detected a large spike in gamma radiation when passing over Mount Brockman, known as Djidbidjidbi to the Mirarr traditional owners of the area. The instrument that detected the anomaly was a Nuclear Enterprises gamma ray spectrometer using a Thallium doped Sodium Iodide cylindrical crystal. At time of discovery the aircraft was flying at an altitude of . The anomaly could still be detected at almost . The crew members on board were Bill Hay, the pilot, Harvey Morton, the navigator and Frank Lanza, the instruments operator, who first recognised the significance of the anomaly. The Ranger Uranium Environmental Inquiry In 1975, Gough Whitlam appointed Justice Russell Fox, a judge of the Supreme Court of the Australian Capital Territory, to lead an inquiry into the environmental dangers posed by mining uranium in the Northern Territory and the associated risks of exporting it, including those of nuclear proliferation. The inquiry produced two reports, published in 1976 and 1977. The ore bodies The Ranger No. 1 and Ranger No. 3 ore bodies occur in the Cahill Formation, consisting of Lower Proterozoic metasediments, located in