234 Adventures in Scenery 



south of Bear Valley the mountains are rugged, and are trav- 

 ersed by steep crooked canyons. On the south flank of the 

 range the extremely rugged topography such as occurs south 

 of San Gorgonio Mountain gives way to low foothills, which 

 are cut by many streams that lead southward to San Gorgonio 

 Pass. 



Drainage from the western part of the San Bernardino 

 Range is southwesterly by the Santa Ana River to the Pacific 

 Ocean. Streams east of Banning and south of Morongo Valley 

 flow into the Salton Sink or disappear in the desert before reach- 

 ing it. Those north of Morongo Valley and Bear Creek flow 

 out upon the Mojave Desert and sink into the sands or are 

 evaporated. 



Alluvial Fans on North and South Slopes 

 of San Bernardino Mountains 



Extensive alluvial fans are built along both the northern 

 and the southern flanks of the main mountain range. Those 

 on the south flank spread out across San Gorgonio Pass. One 

 at the mouth of Mission Creek is well developed and shows the 

 character of such stream deposits. Near the mouth of the can- 

 yon the material making up the fan is mainly a mass of boulders. 

 To the southeast, toward Palm Springs, the material is finer, but 

 even here are large boulders brought down during cloudbursts. 

 The stream is constantly changing from one radiating channel 

 to another across the fan. At the mouth of Millard Canyon 

 the fan is a mass of slightly rounded boulders. At Cabe- 

 7;on, farther down the fan, the alluvium is finer and the land 

 is planted in orchards. At Banning the upper part of the 

 fan contains many boulders brought down by floods of San 

 Gorgonio River, whereas south of the town the soil is fine- 

 grained and fairly heavy. 



Similar deposits made by streams during earlier stages in the 

 uplifting of the mountains occur in many places, on the flanks 

 of the main mountain range, and also along streams that 



