Upper Yosemite Fall drops 1,430 feet, (nine Niagra Falls stacked on top of each other). In the winter the water falling down Yosemite Creek often freezes as it goes over the top, creating a snow cone or ice cone at the base of upper Yosemite Fall.
The Park website tells us: "During winter, sunny days between storms keep the falls in the valley at a trickle; they are transformed into pillars of ice by freezing night temperatures. The Yosemite Falls ice cone forms when water spray, frozen to the granite wall, loosens as it is warmed by the sun and spills to the base of the upper falls.
Water that does not freeze builds up on the cone, and as the temperature continues to rise, the water falls straight into the cone like a reverse volcano. The cone can grow to heights of 250 feet and can cover up to four acres."
John Muir wrote "In winter the thin outer folds and whirling spray of the great Yosemite Fall are frozen while passing through the air freely exposed, and are deposited around the base of the fall in the form of a hollow, truncated cone, which sometimes attains a height of 400 feet.
http://faculty.deanza.edu/donahuemary/stories/storyReader$406
