PHYSICAL GEOGRAPHY 69 



Here, in this little known desert region of the 

 Desert side between the 34th and 35th parallels of 

 north latitude and the north and south ends of the 

 Mojave and Colorado Deserts respectively, is the meet- 

 ing place of three of the most important geographic 

 features of different ages and trends, as may now be 

 seen for the first time by examining the beautiful topo- 

 graphic sheets of that region recently made by the 

 Department of Power and Light of the City of Los 

 Angeles. 



It is not necessary for us to describe further this 

 relatively well known Great Basin Province or its 

 southwest end known as the Antelope Valley portion 

 of the Mojave Desert, as this has been sufficienty done 

 by H. R, Johnson and others. 



THE COLORADO DEPRESSION 



The Colorado Desert or Depression, except in cli- 

 mate, is quite different from the northern, or Great 

 Basin Province. It consists of a north-south ex- 

 tending, near and below sea level, valley plain or 

 trough, one thousand miles long by a hundred miles 

 wide, which lies between and below the highlands of 

 the Peninsula Ranges on the west and the west sides 

 of Southern Arizona and Mexico on the east. The 

 southern and greater part of this area is now beneath 

 the waters of the Gulf of California, while its northern 

 end, formerly an extension of the same, is the partially 

 reclaimed and fertile Colorado Desert portion (Imperial 

 Valley of Southern California and of northern Lower 

 California. 



As a whole, this depression follows a comparatively 

 ancient, north-south-extending trough that may be a 



