16 SOUTHWESTEKN NEVADA AND EASTERN CALIFORNIA. 
Spurr, J. E. The ore deposits of the Silver Peak (Nevada) quadrangle. Prof. 
Paper U. S. Geol. Survey No. 55, 190G. 
Ball, Sydney H. Notes on the ore deposits of southwestern Nevada and 
eastern California. Bull. U. S. Geol. Survey No. 285, 1906, pp. 53-73. 
Ransome, F, L. A preliminary account of Goldfield, Bullfrog, and other min- 
ing districts in southern Nevada ; with notes on the Manhattan district 
by W. H. Emmons and G. II. Garrey. Bull. U. S. Geol. Survey No. 303, 
1906. 
THE GREAT BASIN. 
The Great Basin is an elevated region in Nevada and contiguous 
portions of Oregon, California, and Utah, containing approximately 
208,500 square miles. None of its streams How to the ocean, and in 
this it differs from all other provinces of the United States. The 
region is arid, the precipitation being less than 20 indies a year. 
The scenery, were it not for the grotesque form and bizarre coloring 
of many of the mountains and hills, would be depressingly dreary. 
The mountain ranges of the region for the most part trend north 
and south and are characteristically rugged and bare, although the 
crests of some of the higher ranges are covered by a scant growth o1 
timber. The mountains are cut by deep canyons, and in a few o1 
these streams flow, only to sink in the desert gravels. Associate( 
with the ranges are low hill groups and mesas, many of which als< 
have a north and south elongation. Between the mountains and hilb 
are broad, gently sloping, inclosed valleys, which send branches int( 
mid in places across the mountains. The lowest portion of most oi 
the valleys i^ occupied by either a lake or a playa, which during the 
greater part of the year is a level waste of hard clay, but after heaw 
rains is covered by a thin sheet of water. 
TOPOGRAPHY. 
The area under discussion, a typical portion of the Great Basin, is 
one of mountain ranges and mesas with wide valleys of gentle slope : 
between. To the north of the broad Pahute Mesa lie mountain ranges j 
with a general north-south trend. Southeast of the mesa the nioun- 
tains are small groups whose crest lines run in various directions, j 
The Grapevine and Panamint ranges, southwest of the mesa, extend j 
from northwest to southeast and are in consequence parallel to the 
Sierra Nevada. The relief of the area is great; Kawich Peak is 
0,500 feet above sea level and the part of Death Valley within the area | 
lies 280 feet below sea level. Few of the ranges, however, rise more 
than 3,000 feet above the flat valley, although the mountain front 
on either side of Death Valley reaches an elevation of 7,000 feet j 
within a distance of 12 miles. Between mountains with distinct I 
crests, such as the Kawich Range, and the small hillocks in the desert 
