The depth to which the Valley was cut by streams and glaciers is
measured roughly by the extraordinary height of the waterfalls which
pour over the rim.
The Upper Yosemite Fall, for instance, drops 1,430 feet in one sheer
fall, a height equal to nine Niagara Falls piled one on top of the
other. The Lower Yosemite Fall, immediately below, has a drop of 320
feet, or two Niagaras more. Counting the series of cascades in between,
the total drop from the crest of Yosemite Fall to the Valley floor is
2,565 feet. Vernal Fall has a drop of 317 feet; Illilouette Fall, 370
feet. The Nevada Fall drops 594 feet sheer; the celebrated Bridalveil
Fall, 620 feet; while the Ribbon Fall, highest of all, drops 1,612 feet
sheer, a straight fall nearly 10 times as high as Niagara. Nowhere else
in the world may be seen a water spectacle such as this.
The falls are at their fullest in May and June while the winter snows
are melting. They are still running in July, but after that decrease
rapidly in volume, Yosemite Fall often drying up entirely by August 15
when there has been little rain or snow. But let it not be supposed that
the beauty of the falls depends upon the amount of water that pours over
their brinks. It is true that the May rush of water over the Yosemite
Fall is even a little appalling, when the ground sometimes trembles with
it half a mile away, but it is equally true that the spectacle of the
Yosemite Fall in late July, when, in specially dry seasons, much of the
water reaches the bottom of the upper fall in the form of mist,
possesses a filmy grandeur that is not comparable probably with any
other sight in the world; the one inspires by sheer bulk and power, the
other uplifts by its intangible spirit of beauty. To see the waterfalls
at their best one should visit Yosemite before July 15.