GEOLOGY OF CARRIZO MOUNTAIN, CALIFORNIA 339 



flood periods, when its waters join those of San FeHpe Creek, 

 north of Black Mountain, and eventually reach the Salton depression. 

 At Carrizo Station, one of the relief stations of the old Butterfield 

 stage line, a series of springs rise, and for one or two miles below 

 this point flowing water is found in the creek bed, except during the 

 hottest period of summer. 



The desert floor at the eastern base of the peaks is generally 

 from 100 to 200 feet above sea-level, but on the north side of Black 

 Mountain the sea-level contour and the old beach of Lake Cahuiha,' 

 40 feet above sea-level, swing in against tlje mountain base. In the 

 past the region has been rather diflicult of access, because of its 

 remoteness from settlements and its aridity. With the colonization 

 of the Imperial Valley since 1900 and the building of the branch 

 railroad from Old Beach to Calexico, however, this condition has 

 been greatly modified. Now Carrizo Station or Coyote Well may 

 be reached by one day's drive from Imperial or El Centro, and sup- 

 plies are readily secured at many points in the valley. The old 

 roads from the desert to San Diego, the one running north of Carrizo 

 Mountain by way of Julian and the other south of the mountain by 

 way of Jacumba and Campo, are still much used for direct com- 

 munication between the Imperial Valley and the coast, although the 

 Campo road below Mountain Springs is rough and after storms is 

 nearly impassable. 



EARLIER WORK 



As yet there has been no detailed work done on the geological 

 problems of the extreme southern part of California. Two important 

 reconnaissances, however, have been carried out in that region and 

 a number of other papers contain interesting notes. 



Professor William P. Blake,^ who accompanied one of the Pacific 

 Railroad survey parties under Lieutenant Williamson through 

 Southern California in 1853, wrote a comprehensive account of the 



I Nat. Geol. Mag., XVIII, No. 12, 830. In a note in this number of the 

 National Geographic Magazine, Professor Blake proposes that the name Lake Cahuilla 

 be applied to the vanished water body whose earlier existence is clearly proven by so 

 many phenomena and whose history was first deciphered by Professor Blake himself. 

 The name is most appropriate and the suggestion is most appropriately made by this 

 distinguished worker. 



■" 2 Pacific Railroad Reports, "Geology" (1856), V. 



