Emerald Lake (Yukon)

Emerald Lake, sometimes called Rainbow Lake, gets its colour from the bottom rather than the water: a layer of marl, white calcium carbonate precipitated from the surrounding limestone gravels, coats the shallow bed and reflects blue and green light back up, so the lake reads as a vivid green that changes with depth and light angle. In deeper sections where the marl thins the colour turns blue. It is a roadside stop with a pull-off and interpretive sign on the Klondike Highway, taking a few minutes, and it makes an obvious pairing with the Carcross desert a little further south.

What you actually see

• The green colour - light reflecting off white marl on the lake bed.
• The colour gradient - green in the shallows shifting to blue with depth.
• The roadside viewpoint - a pull-off with interpretation on the highway.
• The limestone setting - the gravels that supply the calcium carbonate.

When to go

May to September; the colour needs sunlight and looks flat on overcast days. The lake freezes in winter. Midday sun shows the effect most strongly.

Honest expectations

It is a five-minute roadside stop with no facilities or trail. Overcast weather removes the colour almost entirely. There is no lake access beyond the viewpoint.

Nearby

Carcross lies south; Whitehorse is north.