One of Canada's foremost mining and refining centres, this region achieved world renown in the field of hard-rock mining. Initially important for silver mining, it emerged in the late 19th century as the leading Canadian producer of gold, primarily at the Rossland Gold Mines. Thereafter, the Kootenays became a world leader in the production of lead and zinc, based on the output of the legendary Sullivan Mine at Kimberley. This achievement was made possible through the development of innovative processes for treating low-grade and complex ores at the Trail smelter and Sullivan Mine.