266 Adventures in Scenery 



posits were crumpled and folded, the river has cut its channel 

 through granitic areas and follows the lowest parts to its en- 

 trance into the canyon below. It is thought that at an earlier 

 time the river flowed north of the Jurupa Mountains. During 

 more recent time the river has shifted its course to the south of 

 these mountains. 



Below Ringon steep rugged hills of hard rock form the walls 

 of the canyon. The river maintained its course across the ris- 

 ing mountain ridge, cutting down its channel as the mountains 

 were uplifted. Terraces as much as 200 feet above the present 

 river bear testimony to the uplifting of the land and the per- 

 sistent cutting of the river to maintain its grade in its progress 

 toward the sea. The Santa Ana River is an "antecedent" river. 

 The river became established before (antecedent to) the pres- 

 ent conditions, and it follows now the path that it followed 

 before the uplifting of the land. It is "antecedent" in that it 

 keeps its way to the sea despite obstructions raised in its path. 

 It was there before the land forms were developed and it has 

 maintained its course in spite of them. It was there before and 

 is still there, part of the year a "lost" river pursuing its way 

 below its own bed, and at flood times a roaring, rampant 

 destructive giant resistlessly sweeping toward the sea. 



How Old Are the Hills? 



"As old as the hills" is a familiar expression. How old are 

 the hills? Movements along fault lines have brought old deep- 

 lying formations high above "young" formations. The Santa 

 Ana Mountains were uplifted to their present height only re- 

 cently geologically. The San Bernardino Mountains were ele- 

 vated to their present height probably within the era in which 

 we live the Quaternary. (They may be still rising.) Are 

 these mountains then old or are they young? Over in the 

 Temescal Valley east of the Santa Ana Mountains movement 

 along fault lines in comparatively recent time cut off drainage 

 and caused a lake to form. In this lake sediments washed from 



