14 INDIANS OF THE SOUTHWEST. 



Clila flows into the Colorado. The average elevation 

 is high, due to the great plateau between the Rio 

 Grande, the Mogollon Mountains north of the Gila, 

 and the Colorado River. This vast tableland, from 

 4000 to 8000 feet high, has on it isolated mountains 

 such as San Mateo (11,389 feet) and San Francisco 

 peaks (12,794 feet), and innumerable flat-topped, 

 sheer-walled mesas. South of the Mogollon Mountains 

 the country tilts down and merges with the low dry 

 semi-desert of southwestern Arizona. The rainfall 

 varies with the elevation from 24 inches at Flagstaff to 

 3 inches along the lower portion of the Gila and averages 

 from 10 to 15 inches over the greater portion of the 

 region. The evaporation is so great that the streams 

 decrease in volume as they proceed from the mountains 

 until many of them disappear entirely. Even the Rio 

 Grande may at times be crossed dry shod at El Paso. 



The higher mountains and much of the high plateaus 

 are covered with heavy grow^ths of pine. Low^er dowTi 

 are diminutive forests of pinon, cedar, and juniper. 

 Below these flourish mesquite and sagebrush and on the 

 lowest portions of the region are the giant cactus and 

 the smaller ones adapted to arid conditions. The 

 plants of greatest importance are the plums, cherries, 

 agave (century plant), the yucca, the cacti, the pinon, 

 and the mesquite. 



With the exception of the buffalo which are conmionly 

 believed not to have crossed the Pecos in any large 

 numbers, all the larger animals of the southern United 

 States were formerly common. From the standpoint 



