234 GEOLOGY OF TRANS-PECOS TEXAS. 



West Texas that are worth mentioning, as the Delaware Creek and Rio 

 Azul or Black River join it in New Mexico. The Rio Grande, between El 

 Paso and its mouth, has no tributaries of any importance on its left or Texas 

 bank. Most of the creeks laid down on the maps are mere drainage channels 

 for rainwater, some of them occasionally with a series of stagnant water pools; 

 but for the most part, during the greater part of the year, they are as dry as 

 they are on the maps. 



The most important of these tributaries are Glenn's Creek, east of the 

 Eagle Mountains; Cibolo Creek, which provides the Shafter Silver Mills with 

 water along the Chinati Mountains; Tarlinga Creek, west of the Corazones; 

 the Tornillo Creek, between the Chisos and St. Jago Mountains; and the 

 Maravillas Creek, with its mouth about 10 miles south of Mt. Stanley, 30 

 miles from the mouth of the Pecos River. 



From the Mexican side the Rio Grande receives at Presidio the Rio Con- 

 chas, the water of which holds out throughout the entire year, which can not 

 be said of the Rio Grande itself above Presidio Del Norte. 



WATER. 



Of all the mountain ranges of West Texas the Apache or Limpia, or as 

 they are commonly named, the Davis Mountains, are the best timbered and 

 well provided with springs and creeks; and wherever wells are sunk water 

 is reached at depths varying from 30 to 40 feet. Pines of 12 and even 24 

 inches in diameter, different species of oak, cedar, hackberry, elm, cotton- 

 wood, etc., grow luxuriantly, but more especially on the north slope of these 

 mountains. 



A number of springs are also found in the Guadaloupe Mountains, which 

 are the sources of the Rio Azul and the Delaware Creek. Between the 

 Guadaloupe Mountains and the Sierra Diabolo are also a number of springs, 

 and there are also located the famous salt lakes of West Texas. 



Less favored with water are the other mountain ranges of Trans-Pecos 

 Texas; but if we except the Quitman Mountains, the Sierra Blanca, and the 

 southeast extension of the Hueco Mountains, isolated springs, or at least in- 

 dications of water, such as so-called sipes, or moist places in the rocks, are 

 found. In many places cotton wood and black sumach indicate moisture in 

 the ground, and it can not be doubted that wells would yield a moderate 

 water supply in some of the mountain ranges. 



Farther off from the mountains, in the flats, water can be expected only 

 at considerable depths. 



PLANTS. 

 The growth of pine seems to have been confined to the Davis Mountains ; but 

 a limited timbering with scrubby cedar, live oak, and Spanish oak, with small 



