was secretly expropriated and transferred to the Canadian Government in 1943-1944 and renamed Eldorado Mining and Refining Limited. Uranium ore from the mine was used in the atomic bomb developments of 1945. Uranium mining continued after World War II. The mine was expensive to operate and grade of the ore was declining, so new technology was brought in to make the isolated mine profitable. The discarded tailings were dredged from the bay when new machinery was installed to recover the uranium content. The underground workings were deepened and the crown corporation sought out additional deposits of uranium across Canada. But in 1960 the original Eldorado Mine was exhausted and closed. In 1975 the Eldorado Mine was dewatered by Echo Bay Mines Limited to recover old silver and copper minerals. All activity ceased in 1982 and Eldorado Mine and the Port Radium settlement was burned and demolished. In 1984 the site was decommissioned as per local standards at the time. In 2006 an agreement was made with the local Deline community about remediation activities, which were completed in 2007. On 31 December 2016, the Canadian Nuclear Safety Commission issued a 10-year license (therefore running until 31 December 2026) to Crown-Indigenous Relations and Northern Affairs Canada permitting long term monitoring and maintenance of the site. The mine is inspected by the Canadian Nuclear Safety Commission once every three years. The COVID-19 pandemic delayed the 2020 inspection until February 2022. Geology The Early Proterozoic Echo Bay Group consists of tuffs, flow rocks, argillite, quartzite, and dolomitic limestone. Uranium ore deposits occur within veins and stockworks which cut through this group, mainly along four parallel fault zones aligned roughly southwest–northeast from Great Bear Lake. The age of uranium mineralization is about 1,400 Ma. References Bibliography External links Eldorado Mine - NWT Historical Timeline - A Prince of Wales Northern Heritage Centre Online Exhibit Mines in the Northwest Territories Uranium mines in Canada Underground mines in Canada Uranium mines