Emerald Lake is a stunning alpine freshwater lake nestled within Yoho National Park in the Canadian Rocky Mountains of British Columbia, situated along the boundary of British Columbia and Alberta. Coordinates place the lake at approximately 51°26′38″N, 116°31′52″W, within one of four contiguous national parks in Canada's Rocky Mountain corridor. The lake drains via the Emerald River and is renowned for its gem-coloured, brilliantly turquoise waters — a product of glacial rock flour suspended in the water column. The surrounding landscape is defined by dramatic mountain peaks, glaciers, and old-growth conifer forest, making it one of the most visually striking alpine lakes in western Canada. The water remains extremely cold year-round, rarely exceeding 4–5°C even during peak summer months, which is characteristic of high-elevation glacially fed lakes in this region.