Wild Swans at Coole, redux

I recently read 'Crossing Open Ground', by Barry Lopez. It's a series of previously-published magazine articles he reworked for the book, and very beautiful. The following passage was written about the hundreds of thousands of snow geese staging at Tule Lake in Northern California during their annual migration.

I remember watching a large flock rise one morning from a plowed field about a mile distant. I had been watching clouds, the soft, buoyant, wind-blown edges of immaculate cumulus. The birds rose against much darker clouds to the east. There was something vaguely ominous in this apparition, as if the earth had opened and poured them forth, like a wind, a blizzard, which unfurled across the horizon above the dark soil, becoming wider and higher in the sky than my field of vision could encompass, great swirling currents of birds in a rattling of wings, one fluid recurved sweep of 10,000 passing through the spaces in another, counterflying flock, while beyond them lattice after lattice passed like sliding walls, until in the whole sky you lost your depth of field and felt you were looking up from the floor of the ocean through shoals of fish.