61 



CALIFOENIAN FIELD NOTES.— III. 



By Ansteutheb Davidson, M. D. 



On Big Rock Creek. 



The western angle of the Mojave Desert lies mostly within 

 the limits of Los Angeles County, and is bounded on the 

 north and west by the Tehachapi, and on the south by the 



Madre „^.^.„^ ^. 



extend from the coast hills eastward. 



The Southern Pamfir? mi^rr^atl niM 



Madr 



range through the Soledad Pass and continues across the desert 

 about thirty miles from its western limit. About forty miles 

 further east the Santa Fe railway crosses the range by the 

 Cajon Pass, the mountains between these passes occupying a 

 belt about twenty-five miles wide, and rising from an eleva- 

 tion of about 3,000 ft. at Soledad, to 10,000 ft. near the Cajon 

 Pass. The desert here lies at an average elevation of 2,500 

 feet, and towards it, from the northern slope of the Sierra 

 Madre range, flow a few mountain streams, the largest of 

 which is Big Eock Creek, about midway between the Soledad 

 and Cajon passes. 



Early in the morning of the 4th of July, 1893, my compan- 

 ion and I left the train near the Soledad Pass and taking 

 team from Harold, an adjoining settlement, we turned our 

 faces eastward across the desert. Our road led us through 

 the usual desert shrubbery of Atriplex and Artemisia, with 

 abundance of SalazariaMexicana,cxowdiedL with its bladdery 

 fruit on which the desert chipmunks were making their morn- 

 ing meal; while over all, the gaunt arms of the Yucca arhor- 

 escens waved like spectres in the morning gloom. For twenty 

 miles we travelled before the foothills, and as we turned 

 southward up the Big Hock Creek we left behind the Larrea 

 Mexicana and the lower Sonoran belt. For the next five 

 miles the road leads along the creek, until we reached a ranch 

 at an elevation of probably 4,400 feet. Here we made head- 

 quarters and began by exploring the creek from where it 

 debouches in the desert to its source in the pine woods on the 

 Sierra slopes. 



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