Mirror Lake is one of the most popular locations for viewing scenery in the Yosemite Valley, because it is beautiful and peaceful, and while easy to access, is far enough away to keep down the crowds. Like everything else in Yosemite associated with water, it is highly seasonal. In the spring, when water levels in the Yosemite Valley run very high, Tenaya Creek is a torrent and Mirror Lake is fairly large. As spring fades to summer, the rivers drop and the lake slowly shrinks; by the end of the summer, most of the water is gone, and there's just a small remnant as seen in this 3x2 panorama.
Mirror Lake is slowly filling in with river-deposited sediment; geologists say that all of Yosemite Valley was once a lake that was filled in over hundreds of years by river sediments in this same manner. For many years the National Park Service dredged to stop the lake from filling in, but consistent with the emphasis in recent decades of preserving natural processes in national parks, this intervention has been discontinued. Thus, one day Mirror Lake will be Mirror Meadow, a name that will seem strange to those who don't know its history...
Mirror Lake is slowly filling in with river-deposited sediment; geologists say that all of Yosemite Valley was once a lake that was filled in over hundreds of years by river sediments in this same manner. For many years the National Park Service dredged to stop the lake from filling in, but consistent with the emphasis in recent decades of preserving natural processes in national parks, this intervention has been discontinued. Thus, one day Mirror Lake will be Mirror Meadow, a name that will seem strange to those who don't know its history...