328 J. LeConte—Ancient Glaciers of the Sierras. 
can fail to perceive them in Yosemite. The bottom of this 
valley, as of all the glacial valleys of the Sierras, consists of a 
succession of level meadows covered with grass and flowers, 
finer material without sorting—in other words, of moraine mat- 
ter. These boulder piles are certainly terminal moraines, and 
the meadows are ancient lakes or marshes, produced by the 
damming up of the river waters by successive terminal moraines 
left by the retreat of the glacier and afterward filled up by 
river silt. 
Tributaries of Merced Glacier.—The north fork of the Mereed 
river now drains the whole area bounded by Mt. Hoffman, 
Cathedral Peak, Mt. Lyell and Mt. Clark. (See map.) Its tribu- 
taries are Yosemite creek coming from Mt. Hoffman, Tenaya 
ereek from Cathedral Peak, and other peaks in the vicinity, the 
“main Merced coming from Mt. Lyell group, and Ililuette from 
Mt. Clark group. In glacial times precisely the same basin was 
drained by the Merced glacier, and there was a tributary glacier 
corresponding to each of these tributary rivers. Only two ©. 
these I have personally examined. Mr. Muir has examined 
them all.» 
(a.) Little Yosemite Glacier. —The most important of these 
tributaries, in fact the main feeder of the Merced glacier, was 
formed by ice streams coming from Cathedral peak, an 
es 
pecially from Mt. Lyell group, which, uniting in Little Yosemite 
valley, passed down as ice cascades over the Nevada falls and 
the Vernal falls, and so joined the other tributaries, especially 
the Tenaya glacier, to form the great glacier which filled Yose- 
mite. At the point of former junction with the Tenaya, as first 
pointed out by Mr. King, a median moraine is still traceable. 
Our route, as already stated, passed up the Nevada cafion to 
the top of the herada falls; thence along the rim of Little 
osemite valley, and thence over a ridge into Feldspar valley 
(F. V.), and up this valley to Cathedral peak. Glaciated surfaces 
and erratics were found nearly all the way. As we pa along 
the edge of the rim of Little Yosemite, we had a magnificent 
bird’s-eye view of the wonderful dome-like form of nearly all 
the prominent points about this valley. Standing thus above, 
and looking down upon them, their striking resemblances to 
glaciated forms cannot be overlooked. The whole surface of the 
country is moutonnée on a huge scale. If so, then the greater 
domes about the Yosemite have been formed in a similar man- 
ner. If so, then the whole surface of this region, with its greater 
and ; er domes, has been moulded beneath an universal ice- 
sheet, or confluent glacier which moved onward with a steady 
