For though summer sun-heat is stored in the rocks of the south side also, the amount is much less because the rays fall obliquely on the south wall even in summer and almost vertically on the north.
The upper branches of the Yosemite streams are buried every winter beneath a heavy mantle of snow, and set free in the spring in magnificent floods.

Then, all the fountains, full and overflowing, every living thing breaks forth into singing, and the glad exulting streams shining and falling in the warm sunny weather, shake everything into music making all the mountain-world a song.
The great annual spring thaw usually begins in May in the forest region, and in June and July on the high Sierra, varying somewhat both in time and fullness with the weather and the depth of the snow.

Toward the end of summer the streams are at their lowest ebb, few even of the strongest singing much above a whisper they slip and ripple through gravel and boulder-beds from pool to pool in the hollows of their channels, and drop in pattering showers like rain, and slip down precipices and fall in sheets of embroidery, fold over fold.

But, however low their singing, it is always ineffably fine in tone, in harmony with the restful time of the year.
The first snow of the season that comes to the help of the streams usually falls in September or October, sometimes even is the latter part of August, in the midst of yellow Indian summer when the goldenrods and gentians of the glacier meadows are in their prime.

This Indian-summer snow, however, soon melts, the chilled flowers spread their petals to the sun, and the gardens as well as the streams are refreshed as if only a warm shower had fallen.