On a June afternoon, Glacier National Park's Lake MacDonald reflected the same shade of blue as a breaking Hawaiian wave. As I walked into the chilly waters, both the size and the whiteness of my feet seemed amplified against the red and grey cobbles.
Gradually, my submerged legs adjusted to the cold. I took a couple more steps forward, winced, and looked ahead to distract myself. In the distance stood a forest of cedar trees. Higher up, the trees surrendered to the permanent coldness, leaving bare rocky slopes where mountain goats forage for alpine grasses. A few glaciers still filled the highest cloud covered valleys.
I entered the all or nothing phase of mountain lake swimming. I needed either to exit or dive in and start swimming.
I plunged. I did my best crawl for 25 yards or so, until my moving muscles dispelled the chill. Renewed, I treaded water, enjoyed the liberation from two days of tent dust and sweat, and took in the view.
The movement of the clouds across the lake created evolving patches of turquoise, royal, and navy blue. During a ranger talk that morning, I found out that the lake's unique color comes from the glaciers grinding the sedimentary rock below them to a flour-like consistency. The meltwater then flows into the lake, scattering mostly blue light into a plethora of variations.