SHASTA ROUTE SEATTLE TO SAN FEAXCISCO. 



69 



stone and conglomerate, 

 older rocks of the Kl 



through fossiliferous Upper Cretaceous (Chico) sand- 



These rocks unconformably overlap the 



On the right the bluff affords a section of the sands and gravels of the 



VaUey. 



formation, which 



but the nights are cool and the air dry^ 

 The winter temperature seldom falla 

 below freezing, and IS"* above zero is the 

 lowest temperature recorded in 60 years. 

 Snow is almost unknown. 



The character of the climate is reflected 

 in tlie life of the people. With the begin- 

 ning of the rains in the fall grass springs up 

 and cattle and sheep are brought down 

 from the mountains where they have 

 passed the summer. The overflowed tule 

 lands in the center of the valley are grazed 

 in the long dry summer, but with the 

 coming of the rains the cattle are taken to 

 the higher plains. The grain farmer sows 

 his wheat and bailey in the fall and har- 

 vests them early in the summer. He lets 

 his land lie fallow after the rains, to be 

 planted drj- in the fall. All the decidu- 

 ous fruits bear heavily and are rarely 

 damaged by frost. The more delicate 

 fruits and nuts — apricots, almonds, wal- 

 imts, olives, lemons, and oranges — grow 

 well when assisted by irrigation. There 

 are large areas of vineyards and the long 

 dry season is favorable to the concentra- 

 tion of sugar in the grape and to the drj^'- 

 ing of the grapes to make raisins. 



tent. Because of this oxidation it is 

 characteristically red. 



The deposition of the older alluvium 

 was followed by uplift in both the Sierra 

 Nevada and the Coast Eange. The 

 edges of the vallej' were bent up and the 

 middle gently boAved doAvn. In conse- 

 quence of this movement the older allu- 

 vium was uplifted along the borders of 

 the valley, and streams began to cut into 

 it. At this time began the deposition 

 of the younger alluvium, which has con- 

 tinued to the present day. This material 

 floors by far the larger part of the valley 

 and is as varied in chai'acter as the older 

 alluvium. The deposits are compara- 

 tively thin, probably nowhere in the 

 valley over 300 to 400 feet thick. Every 

 high water adds to them, and this is so 

 well understood that farmers have been 

 known to deliberately turn flood waters 

 on their land for the benefit derived from 

 the sediment left behind. 



The recent allu\ium is the most pro- 

 ductive water bearer of the valley forma- 

 tions, largely because its gravels and 

 sands are uncemented and porous. The 

 water usually lies within 25 feet of the 



The agricultural character of the valley surface, but its level fluctuates with the 

 is closely related to its geologic history, seasons. This fluctuation is seldom more 



than 10 to 15 feet, a fact which indicates 

 that a much larger volume of water is 



With the uplift of the Sierra Nevada and 

 Coast Range in Pliocene time the valley 

 became land, and deposition of alluvial 

 materials began under conditions similar 

 to those of the present time. 



The alluvium is of two kinds— an older 

 and a younger. The older alhndum is of 

 PleLstocene or possibly of late Pliocene 

 age and rests on the eroded edges of Mio- 

 cene and older rocks. It is composed of 

 <^^ay, sand, and gravel and varies mucli in 



appearance and composition. It is dis- 

 tinguished from the younger alluvium by 

 the fact that it is now undersoino^ dis- 

 section by etreams and by the greater 

 oxidation and dehydration of itairon con- I replacing the old-time rancher. 



available than is at present utilized. 



The Sacramento Valley is now in a 

 state of rapid change. The overflowed 

 lands are being divided into large districts 

 for reclamation by levees and drainage. 

 After reclamation they are cut up into 

 small lots and colonized. Grain ranches 

 are being subdivided and sold in small ir- 

 rigates! tracts. In consequence the popu- 

 lation 19 increasing and its character is 

 changing. The keen, intelligent irrigator, 



raising special crops, living a conmiunity 

 life, and keeping abreiist of the times, is 



