438 University of California Publications in Geology [Vol. ll 



GEOGRAPHIC SITUATION AND EXISTING PHYSICAL 

 CONDITIONS IN THE MOHAVE AREA 



The Mohave area is a province or subdivision of the Great Basin 

 region, of which it forms the southwest corner. The Great Basin 

 is separated from the Coast or Pacific region on the northwest side 

 of the Mohave area by the abruptly rising Sierra and Tehachapi 

 ranges. On the southwest side of the Mohave, the San Bernardino, 

 San Gabriel, and other ranges extending between the San Gabriel 

 and the Tehachapi, form a clearly marked boundary. 



To the north the Mohave area extends into valleys between the 

 parallel ranges situated to the east of Owens Lake. To the northeast 

 it grades almost insensibly into the Middle Basin or Nevada area of 

 the Great Basin. A natural boundary seems to be fixed by a range 

 running nearly parallel with the California-Nevada line southeast of 

 the Amargosa Range. To the east the Mohave area may be limited 

 by more or less irregular groups of mountain ranges lying between 

 the San Bernardino Range and the Opal Mountains and Dead Moun- 

 tains west of the Colorado River at the southern end of Nevada. 

 Considering this area in a broad sense, rather than as limited strictly 

 to the Mohave Desert, the Mohave area seems naturally to reach east 

 and southeast to the western border of the plateau, lying to the east 

 of the Colorado River. 



The Mohave area is in general one of extreme aridity at the 

 present time. The rainfall is about five inches in the western portion 

 of the desert near the town of Mohave, and may be one or two 

 inches less in the region farther to the east, near Barstow. Living 

 streams are rare, and travel in all of this region has necessarily been 

 limited by scarcity of localities at which potable water can be 

 obtained. In recent years the development of artesian water has made 

 agricultural operations possible in regions which previously had been 

 uninhabitable. 



