1912] 



Baker: Western El Paso Range 



119 



THE WESTERN EL PASO RANGE 



Previous Investigations 



The only geologists who have written of the western El Paso 

 Range are G. K. Gilbert, 1 H. W. Fairbanks, 2 and the writer. 3 

 The easternmost portion of the range will be described by F. L. 

 Hess in the forthcoming Randsburg folio of the United States 

 Geological Survey. 



Geography 



The El Paso Mountains form a low, even-crested, and, for the 

 most part, maturely dissected ridge lying en echelon with the 

 southern Sierra Nevada along the northern boundary of the 

 Mohave Desert. They trend east-northeast and west-southwest 

 for their entire length of twenty miles and are about six times 

 as wide near their eastern extremity as near their western. 

 They reach their highest summit in Black Mountain, a short 

 distance west of the region mapped on the Randsburg topo- 

 graphic sheet of the United States Geological Survey. Eastward 

 of Black Mountain the range continues into the region of the 

 northwestern portion of the Randsburg sheet and comes to an 

 end about three miles east of the boundary line between Kern 

 and San Bernardino counties and some six to eight miles north 

 of the mining camp of Randsburg. The southern base of the 

 El Paso Range is skirted by the California and Nevada broad- 

 gauge railroad, a branch of the Southern Pacific System. 



The El Paso Mountains are separated on the north from the 

 Sierra Nevada by a southward-sloping alluvium-mantled plain 

 ranging in width from six or eight miles east of Walker Pass 

 to less than two miles at the west, north of Cantil station on the 



1 Eeport on the geology of portions of Nevada, California, and Arizona, 

 examined in the years 1871 and 1872, Geog. and Geo]. Expl. and Surv. west 

 of the Hundredth Meridian, vol. 3, pp. 142 and 143, 1875. 



2 Notes on the geology of eastern California, Am. Geol., vol. 17, pp. 63- 

 74, 1896. 



3 Notes on the later Cenozoie history of the Mohave Desert region in 

 southeastern California, Univ. Calif. Publ. Bull. Dept. Geol., vol. 6, pp. 333- 

 383, 1911. 



