224 
GEOLOGY. 
among the Lost Mountains, all of which appear to he constant and capable of supplying a large 
quantity of water. 
At our Depot Camp on the Mojave River, the water we used was not obtained from the stream, 
but from a large spring gushing out of a bank elevated several feet above the river, and three 
or four hundred yards from it. This spring forms a pool about twenty feet in diameter, and 
from one to one and a half feet in depth. The bottom is sandy, and a stream of clear water 
flows rapidly away from it. This water is warm ; and on cold, frosty mornings, before the sun 
has risen, is enveloped in a cloud of fog, or “ steam.” On the 7th of October, at 2 p. m., I 
found its temperature to be 73° F., the air being 60°. On the 8th, at daylight, air 36°, water 
72°, and the ground around the spring covered by frost. 
There is another large spring on the Spanish trail, not far from the lower end of the Mojave, 
called Agua de Tomaso, or Agua de Tio Mes. This is a pool about six feet in diameter, 1 from 
which bitter water flows for about one hundred yards. Three or four smaller springs are found 
in the vicinity, or within a radius of fifty yards, and all of them are fringed with grass. These 
springs are on the side of the hill, and are constant. 
Other springs in this vicinity, and further north, are mentioned by Colonel Fremont. 2 Some 
of these were salt, but others, beyond the stream of bitter water called Armagosa, were fresh 
and excellent. The camping ground called Archilette is in a basin well supplied by springs, 
bordered by willows and grass ; between this place and Las Vegas there is another, which 
Colonel Fremont called Hernandez Spring. The springs called Las Vegas are described as 
large and slightly warm, the temperature being 71° to 73°. They form two narrow streams of 
clear water four or five feet deep, flowing with a quick current. It is probable that these last 
springs are without the crest, or divide, of the boundary of the Basin, being near the sources 
of the Rio Virgen, a tributary of the Colorado. 
The configuration of the surface of the Basin, and its subordinate interior basins of small 
extent, is favorable to the production of springs, and to subterranean currents of water. This 
statement is verified by the number and extent of the springs that have been described. In 
nearly every case the camping ground of the traveller is not on the bank of a brook or river, 
but at springs or pools of water. Even the Mojave, below the point where it sinks for the first 
time, may be considered as a chain of springs ; for the phenomena of its subterranean flow and 
re-appearance at distant points are precisely those of springs, which, in fact, are but outbursts 
of underground rivulets or brooks, or the outlets of a collection of water in a basin-shaped 
depression, forming a subterranean lake. These natural fountains of water are, indeed, the 
only dependence, for days together, of the traveller of those semi-desert regions. No shaded 
groves or running streams, bordered by a rich growth of timber, greet his eye; but in some 
hidden valley, walled in by brown and sombre ridges, he sees a dark spot on the parched 
and sandy surface, and singles it out as his camping place for the night, recognizing in the 
familiar tuft of willows indications of the water he so earnestly desires. 
POSSIBILITY OF OBTAINING WATER BY ARTESIAN WELLS. 
The facts which have been presented regarding the rivers and springs of the Basin are suffi¬ 
cient to show that a large and constant supply of water is thrown into it from the interior 
slopes of the Sierra Nevada and the Bernardino Sierra. 
1 According to Lieutenant Williamson, who visited it. 
3 Report .of an Expedition to the Rocky Mountains, Senate Doc. 174, p. 263-266. 
