Ekati Diamond Mine and Stewart Blusson who had been prospecting in the region for almost ten years, having found kimberlite indicator minerals as early as 1985. The Point Lake kimberlite was determined to be uneconomic, but its discovery precipitated one of largest staking rushes in mining history, covering most of the area between Yellowknife and the Arctic coast. There are 156 known kimberlite pipes within the Ekati block of claims, including the Point Lake pipe. Ekati officially began operations on October 14, 1998, and was operated by BHP Billiton Canada Inc., a part of the BHP Billiton Group, the world's largest diversified resources
Permafrost down to . Discontinuous permafrost is often further divided into "extensive discontinuous permafrost", where permafrost covers between 50 and 90 percent of the landscape and is usually found in areas with mean annual temperatures between , and "sporadic permafrost", where permafrost cover is less than 50 percent of the landscape and typically occurs at mean annual temperatures between . In soil science, the sporadic permafrost zone is abbreviated SPZ and the extensive discontinuous permafrost zone DPZ. Exceptions occur in "un-glaciated" Siberia and Alaska where the present depth of permafrost is a relic of climatic conditions during glacial ages where winters