The observer sits on the very edge of the fountain amphitheaters still holding large masses of snow; immediately below, almost at his feet, lie glistening, gem-like, in dark rocky setting, the three exquisite little lakes; on either side of these, embracing and protecting them, stretch out the moraine arms, reaching toward and directing the eye to the great Lake, which lies, map-like, with all its sinuous outlines perfectly distinct, even to its extreme northern end, twenty-five to thirty miles away.  As the eye sweeps again up the canyon-beds, little lakes, glacier scooped rock basins, filled with ice-cold water, flash in the sunlight on every side.  Twelve or fifteen of these may be seen.

    From appropriate positions on the surface of Lake Tahoe, also,
    all the moraine ridges are beautifully seen at once, but the
    glacial lakes and the canyon-beds, of course, cannot be seen.

    There are several questions of a general nature suggested by
    my examination of these three glacial pathways, which I have
    thought best to consider separately.

a.  Evidences of the existence of the Great Lake Valley Glacier.  On the south shore of Lake Tahoe, and especially at the northern or lower end of Fallen Leaf Lake, I found many pebbles and some large bowlders of a beautiful striped agate-like slate.  The stripes consisted of alternate bands of black and translucent white, the latter weathering into milk-white, or yellowish, or reddish.  It was perfectly evident that these fragments were brought down from the canyon above Fallen Leaf Lake.  On ascending this canyon I easily found the parent rock of these pebbles and bowlders. the It is a powerful outcropping ledge of beautifully striped siliceous slate, full of fissures and joints, and easily broken into blocks of all sizes, crossing the canyon about a half mile above the lake.  This rock is so peculiar and so easily identified that its fragments become an admirable index of the extent of the glacial transportation.  I have, myself, traced these pebbles only a little way along the western shores of the great Lake, as my observations were principally confined to this part; but I learn from my brother, Professor John LeConte, and from Mr. John Muir, both of whom have examined the pebbles I have brought home, that precisely similar fragments are found in great abundance all along the western shore from Sugar Pine Point northward, and especially on the extreme northwestern shore nearly thirty miles from their source.  I have visited the eastern shore of the Lake somewhat more extensively than the western, and nowhere did I see similar pebbles.  Mr. Muir, who has walked around the Lake, tells me that they do not occur on the eastern shore.  We have, then, in the distribution of these pebbles, demonstrative evidence of the fact that Fallen Leaf Lake glacier was once a tributary of a much greater glacier which filled Lake Tahoe.