A short side-glacier came in against it from the slopes of Clouds' Rest; but being fully exposed to the sun, it was melted long before the main trunk, allowing the latter to deposit this portion of its moraine undisturbed.

Some conception of the size and appearance of this fine moraine may be gained by following the Clouds' Rest trail from Yosemite, which crosses it obliquely and conducts past several sections made by streams.

Slate boulders may be seen that must have come from the Lyell group, twelve miles distant.

But the bulk of the moraine is composed of porphyritic granite derived from Feldspar and Cathedral Valleys.
On the sides of the moraines we find a series of terraces, indicating fluctuations in the level of the glacier, caused by variations of snow-fall, temperature, etc., showing that the climate of the glacial period was diversified by cycles of milder or stormier seasons similar to those of post-glacial time.
After the depth of the main trunk diminished to about five hundred feet, the greater portion became torpid, as is shown by the moraines, and lay dying in its crooked channel like a wounded snake, maintaining for a time a feeble squirming motion in places of exceptional depth, or where the bottom of the canyon was more steeply inclined.

The numerous fountain-wombs, however, continued fruitful long after the trunk had vanished, giving rise to an imposing array of short residual glaciers, extending around the rim of the general basin a distance of nearly twenty-four miles.