Eldorado Mine is located at Port Radium, Northwest Territories, Canada. Radium, uranium and silver were extracted from the mine during several working periods between 1932 and 1982. Uranium from Eldorado was used in the Manhattan Project. The Eldorado Mine is also known as Port Radium, a name adopted for use at this specific site after 1942. The name Port Radium had previously referred to government facilities at Cameron Bay (post office and wireless radio station).
During a field trip along the east arm of Great Bear Lake in August 1900, James McIntosh Bell of the Geological Survey of Canada noted evidences of iron, copper, uranium and cobalt in the vicinity of Echo Bay. Thirty years later, on May 16, 1930, prospector Gilbert LaBine discovered high-grade pitchblende and silver at this site. His company was then known as Eldorado Gold Mines Limited (later renamed Eldorado Mining and Refining Limited).
Eldorado started off as a radium mine in 1932, extracting radium from pitchblende. Radium ores were highly valued at the time because the price of radium salts, used in cancer treatment and then monopolized by Belgium, was US$70,000 per gram. The first concentration plant was a big erection at the site by Allis-Chalmers of Canada in 1933–1934, with a radium refinery built at Port Hope, Ontario. Concentrates and cobbed material were shipped by barge and air plane to rail head at Fort McMurray, Alberta, then by train to Port Hope.