[1] The company was originally established by brothers Charles and Gilbert LaBine as a gold mining enterprise in 1926,[2] but transitioned to focus on radium in the 1930s and uranium beginning in the 1940s.
The company reopened the mine at Port Radium in 1942 to supply the United States military with uranium products.
The Government of Canada nationalized the company by purchasing share control in 1943. and in early 1944 the name was changed to Eldorado Mining and Refining Limited.
[4] Together with a discovery of the Port Radium deposits, the Eldorado company opened the Beaverlodge Mine at Uranium City, Saskatchewan.
Port Hope has the largest volume of historic low-level radioactive wastes in Canada, created by Eldorado Mining and Refining Limited and its private sector predecessors.