Peyto Lake is the colour that people mean when they say glacial turquoise, and in the flesh the blue-green is so intense that photographs seem to have been tampered with. The colour comes from rock flour, fine particles of stone ground off the mountain by the Peyto Glacier and carried into the lake in meltwater. The particles stay in suspension and scatter the light, so the water turns a luminous, milky blue that changes with the season, the sunlight and the amount of melt. It is at its most vivid in July and early August.
The viewpoint is a short walk from the car park at Bow Summit, the highest point on the Icefields Parkway at about 2,100 metres. A paved path climbs through subalpine forest for about ten minutes to a wooden platform at the cliff edge, and the lake lies spread out below, shaped, so they say, like the head of a wolf, with the river flowing in at the far end. The mountains, including Caldron Peak and Mount Patterson, stand around it, and on clear days you can see the whole valley. The lake is named after Bill Peyto, a guide, trapper and park warden in the early twentieth century, known for his tall tales and for keeping a pet bear, a colourful character in a colourful history.
For riders, this is among the busiest stops on the parkway, and the car park fills by mid-morning in July and August. Arrive before nine, or after five, to find a space for the bike and quiet on the platform. Dress warmly: the summit is cool, and snow can linger on the path into June. Wear boots or sturdy shoes for the walk, since riding boots slip on the wet planks. Stay on the marked paths, because the subalpine meadows are fragile, and the park staff have fenced off areas that were damaged by visitors.
The nearest stations are at Lake Louise and at Saskatchewan Crossing, so top up before you set out. The road north from the pass drops in a series of long bends toward the Mistaya valley and the crossing, with views of the Waputik and the Mistaya canyon. The best months are July to September, and in September the larches turn gold in the hills, and the crowds thin.