Mirror Lake is a meadow. Supposedly in the spring time it’s a lake once more, but I am beginning to doubt the rumors. I was there a few years ago, pretty sure it was summer, and it was definitely a lake. A very reflective one.
Apparently we used to dredge the sandy silt from the bottom of the lake every year. [By ‘we’ of course I mean people who lived before I was born, and even before my parents were born, to whom I have no connection except that once they too stood, dwarfed and amazed, in Yosemite Valley.] This served two functions: first it provided sand for the icy winter roads in the area, second it cleared out the lake floor of new buildup, thereby [unnaturally] keeping the lake at about the same depth for decades.
We [the very same] stopped dredging in 1971. So the silt has been building up as nature intended since then and slowly but surely Mirror Lake is turning into a meadow. We [this time I mean me, and my family] saw it on Saturday. We took my dad, a Yosemite first-timer, for a Valley Floor hike and tour and one stop was the lake. I mean meadow.
It was so shocking to see a sandy-floored flood plain with shrubs and trees, and just the slightest trickle of a creek flowing through. You think about how long it has taken to create Yosemite Valley, how many glaciers and rock falls and waterfalls had spent centuries crafting it. Then you see Mirror Lake Meadow (will this be its somewhat nonsensical name in a few more years?) converting almost before your eyes.
Rockfall creates damn across the river; river pools into a fairly mellow lake; river washes sand and rocks into the lake, which are stopped by the rock dam; and VOILA! lake becomes a meadow. How long until the meadow becomes a forest with a river pushing through it, falling over an old rock dam?
Mother Nature kicks ass.