ith numerous streams,
and even considerable rivers, falling into them. In fact, all concur
in the general report of these interior rivers and lakes; and, for
want of understanding the force and power of evaporation, which so
soon establishes an equilibrium between the loss and supply of waters,
the fable of whirlpools and subterraneous outlets has gained belief
as the only imaginable way of carrying off the waters which have no
visible discharge. The structure of the country would require this
formation of interior lakes; for the waters which would collect
between the Rocky Mountains and the Sierra Nevada, not being able
to cross this formidable barrier, nor to get to the Columbia or the
Colorado, must naturally collect into reservoirs, each of which would
have its little system of streams and rivers to supply it. This would
be the natural effect; and what I saw went to confirm it. The Great
Salt Lake is a formation of this kind, and quite a large one; and
having many streams, and one considerable river, four or five hundred
miles long, falling into it. This lake and river I saw and examined
myself; and also saw the Wahsatch and Bear River Mountains which
inclose the waters of the lake on the east, and constitute, in that
quarter, the rim of the Great Basin. Afterwards, along the eastern
base of the Sierra Nevada, where we traveled for forty-two days, I saw
the line of lakes and rivers which lie at the foot of that Sierra; and
which Sierra is the western rim of the Basin. In going down Lewis's
Fork and the main Columbia, I crossed only inferior streams coming in
from the left, such as could draw their water from a short distance
only; and I often saw the mountains at their heads, white with snow;
which, all accounts said, divided the waters of the _desert_ from
those of the Columbia, and which could be no other than the range of
mountains which form the rim of the Basin on its northern side. And in
returning from California along the Spanish trail, as far as the
head of the Santa Clara Fork of the Rio Virgen, I crossed only small
streams making their way south to the Colorado, or lost in sand--as
the Mo-hah-ve; while to the left, lofty mountains, their summits white
with snow, were often visible, and which must have turned water to the
north as well as to the south, and thus constituted, on this part, the
southern rim of the Basin. At the head of the Santa Clara Fork, and
in the Vegas de Santa Clara, we crossed the ridge