New leaves and grasses in Cook's Meadow

The progression of spring in Yosemite is marked by a series of specific events—the tree-frog chorus in Cook’s Meadow, the return the of the red-winged blackbirds, the poppy display in the Merced River Canyon, the redbud bloom, the disintegration of the ice cone at the base of Upper Yosemite Fall, the first bright green leaves of the deciduous trees, the dogwoods blooming, and the Tioga Pass Road opening.

All these events are predictable and yet unpredictable—they always happen every spring, in more or less the same order, but the timing and intensity vary. Last year the poppies started blooming in late February—a bit earlier than average—and the color grew and spread into the most spectacular display I’ve ever seen in the Merced River Canyon. This year the poppies first appeared around the same time, but the bloom never developed the same way. Yet the redbud, which produced a mediocre display last year, were spectacular this spring. Rainfall, temperature, fire, and ash all effect the bloom in unanticipated ways.

One of my favorite oaks with new reddish leaves

Now it’s mid-April, and in some years the deciduous trees in Yosemite Valley—the black oaks, big-leaf maples, cottonwoods, and alders—would be sprouting new leaves. This year, while March was warm and dry, April has been cool and damp. About a foot of snow covered the valley floor on April 5th, and another 4 inches fell this past Monday, April 12th. So the trees are holding back, waiting for warmer weather and a safer time to put energy into their new leaves. For now the meadows are still brown, and the deciduous trees bare except for tiny buds.

For five months the primary colors have been the grays and browns of the cliffs and meadows, with patches of dark green from the pines and cedars, blue from the sky, white after a snowstorm, and occasional flashes of orange or red at sunset. When the leaves finally emerge, and new grasses begin sprouting from the meadows, the valley is suddenly transformed, and large swaths of brilliant green dominate the view.

But there’s a strange outlier among the deciduous trees: the black oaks. On some of these trees the new leaves emerge orange or even red, appearing as if autumn has made an unexpected return.

The "kick" near the top of Upper Yosemite Fall

As all these spring events unfold the snowmelt quickens and the water flow increases. This happens gradually, almost imperceptibly, and is subject to constant temperature-induced fluctuations, but a few signs mark the rising water levels. One is a large, flat rock in the middle of the river just above the “dam”—actually the spot where a small hydroelectric dam used to be, at the junction of Highways 140 and 120. Claudia and I check this rock each time we drive by. When the water is really high, perhaps in late May or early June in a big snow year, the flat rock is completely covered by the river.

Another sign is the “kick” at the top of Yosemite Falls. With moderate to high flows, the water pours over the lip of the upper fall, then about 100 feet down it strikes a small ledge and kicks out into space. But when the falls really get cranking, when it’s full spring-flood-water-everywhere-constant-thundering-roar time, so much water pours over the falls that the kick gets smothered; enough liquid shoots our directly from the lip to bury the water that hits the ledge.

Meanwhile, as we await the peak flood, I’m enjoying the redbud still blooming near El Portal, and looking forward to the rest of spring unfolding. I’ve watched it happen many times, but no two years are the same. Change is constant in Yosemite, as everywhere.

This entry was posted on Friday, April 16th, 2010 at 1:12 pm and is filed under 25 Years in Yosemite. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.