A colour that comes from ground-up rock.
The first thing anyone notices about Lake Louise is the colour — a saturated turquoise that looks almost artificial, especially against the dark green of the surrounding spruce and fir forest and the grey-white of the peaks behind it. The explanation is entirely geological: Victoria Glacier, sitting at the western end of the lake on the slopes of Mount Victoria, grinds against the bedrock beneath it as it moves, producing extremely fine sediment known as "rock flour." This sediment is carried into the lake by glacial meltwater, where it stays suspended in the water rather than settling, and scatters sunlight in a way that produces the lake's distinctive blue-green colour — most intense in July and August, when glacial melt peaks.
The lake itself is modest in size — about 2.4 km long and roughly 70 metres at its deepest — but its setting does most of the work. Victoria Glacier and Mount Victoria dominate the view from the eastern shore, framing the water on three sides with a wall of ice and rock that barely seems to change regardless of the season, while the lake's colour shifts dramatically between the milky turquoise of summer and the white, frozen surface of winter.
The lake's name has its own layered history. The Stoney Nakoda First Nations called it Ho-run-num-nay — "Lake of the Little Fishes." In 1882, Tom Wilson, the first European to document the lake, named it Emerald Lake. Two years later, it was renamed Lake Louise, after Princess Louise Caroline Alberta, a daughter of Queen Victoria — the same princess after whom the province of Alberta is named.
Visitor tip: The lake's colour is most vivid during summer (particularly July and August) when glacial meltwater flow is highest. In winter, the lake freezes over entirely and is sometimes used for ice skating, offering a completely different — but equally striking — view of the same basin.
