ties a number of creeks or so-called rivers, with beds that are
normally dry, flow centrally toward the desert of Salton Sink or "Sea";
this is the lowest part of a large area that is depressed below the
level of the sea,--at Salton 263 ft., and 287 ft. at the lowest point.
In 1900 the Colorado river (q.v.) was tapped south of the Mexican
boundary for water wherewith to irrigate land in the Imperial Valley
along the Southern Pacific railway, adjoining Salton Sea. The river
enlarged the canal, and finding a steeper gradient than that to its
mouth, was diverted into the Colorado desert, flooding Salton Sea;[1]
and when the break in this river was closed for the second time in
February 1907, though much of its water still escaped through minor
channels and by seepage, a lake more than 400 sq. m. in area was left. A
permanent 60 ft. masonry dam was completed in July 1907. The region to
the east of the Sierra, likewise in the Great Basin province, between
the crest of that range and the Nevada boundary, is very mountainous.
Owen's river runs through it from north to south for some 180 m. Near
Owen's lake the scenery is extremely grand. The valley here is very
narrow, and on either side the mountains rise from 7000 to 10,000 ft.
above the lake and river. The Inyo range, on the east, is quite bare of
timber, and its summits are only occasionally whitened with snow for a
few days during the winter, as almost all precipitation is cut off by
the higher ranges to the westward. Still further to the east some 40 m.
from the lake is Death Valley (including Lost or Mesquite Valley)--the
name a reminder of the fate of a party of "forty-niners" who perished
here, by thirst or by starvation and exposure. Death Valley, some 50 m.
long and on an average 20-25 m. broad from the crests of the inclosing
mountain ranges (or 5-10 m. at their base), constitutes an independent
drainage basin. It is below sea level (about 276 ft. according to recent
surveys), and altogether is one of the most remarkable physical features
of California. The mountains about it are high and bare and brilliant
with varied colours. The Amargosa river, entering the valley from
Nevada, disappears in the salty basin. Enormous quantities of borax,
already exploited, and of nitrate of soda, are known to be present in
the surrounding country, the former as almost pure borate of lime in
Tertiary lake sediments.

The physiography of the state is the evident determinant of its c