moraine, are very distinct.  At the head of the lake there is a perpendicular cliff over which the river precipitates itself, forming a very pretty cascade of 100 feet or more.  On ascending the canyon above the head of the lake, for several miles, I found, everywhere, over the lip of the precipice, over the whole floor of the canyon, and up the sides 1000 feet or more, the most perfect glaciation.

There cannot, therefore, be the slightest doubt that this also is the pathway of a glacier which once ran into Lake Tahoe.  After coming down its steep rocky bed, this glacier precipitated itself over the cliff, scooped out the lake at its foot, and then ran on until it bathed its snout in the waters of Lake Tahoe, and probably formed icebergs there.  In its subsequent retreat it seems to have dropped more debris in its path and formed a more perfect terminal moraine than did Fallen Leaf Glacier.

Emerald Bay Glacier.  All that I have said of Fallen Leaf Lake and Cascade Lake apply, almost word for word, to Emerald Bay.  This beautiful bay, almost a lake, has also been formed by a glacier.  It also is bounded on either side by moraines, which run down to and even project into Lake Tahoe, and may be traced up to the rocky points which form the mouth of the canyon at the head of the bay.  Its eastern moraine, as already stated, is partly merged into the western moraine of Cascade Lake, to form a huge medial moraine.  Its western moraine lies partly against a rocky ridge which runs down to Lake Tahoe to form Rubicon Point.  At the head of the bay, as at the head of Cascade Lake, there is a cliff about 100 feet high, over which the river precipitates itself and forms a beautiful cascade.  Over the lip of this cliff, and in the bed of the canyon above, and up the sides of the cliff-like walls, 1000 feet or more, the most perfect glaciation is found.  The only difference between this glacier and the two preceding is, that it ran more deeply into the main lake and the deposits dropped in its retreat did not rise high enough to cut off its little rock basin from that lake, but exists now only as a shallow bar at the mouth of the bay.  This bar consists of true moraine matter, i.e., intermingled bowlders and sand, which may be examined through the exquisitely transparent water almost as perfectly as if no water were present.  All that I have described separately and in detail, and much more, may be taken in at one view from the top of Mount Tallac.  From this peak nearly the whole course of these three glaciers, their fountain amphitheaters, their canyon beds, and their lakes enclosed between their moraine arms, may be seen at once.  The view from this peak is certainly one of the finest that I have ever seen.  Less grand and diversified in mountain forms than many from peaks above the Yosemite, it has added beauty of extensive water surface, and the added interest of several glacial pathways in a limited space.