62 



GUIDEBOOK OF THE WESTERI^ UNITED STATES. 



>uts against tlie footliills of the Klamath 

 seen on the right (west) on the way 

 down to Sisson probably represent a lake whose waters were held 

 a<rainst the natural dam of the moraine. In course of time the lake 



Mountains, 



meadows 



became a meadow 



morainal 



is well exposed at Upton, is used for track ballast. 



About li rtiih^K north of Sisson (338 miles 



railro 



This is some- 



Sacramento 



Sacramento 



of this spring. 



Sisson. 



Elevation 3,594 feet. 

 Seattle 619 miles. 



Mount Shasta (PL XXI) stands out majestically from Sisson and 



may be ascended from this point, A good trail, about 

 6 miles in length, leads to Timberline camp, and from 

 this camp the summit, 6,000 feet higher, may be 

 reached and the return made to Sisson in a day. 

 That temperature and moisture control the distribution of plants 

 and animals is well illustrated by the strong contrast between the 



flora of Mount Shasta 

 and that of Shasta 

 Valley, The summit 

 of Shasta is bare of 

 vegetation because of 

 cold, and Shasta Val- 

 ley, 10 miles away, is 

 treeless for lack of 

 moisture. Between 

 these extremes lies the 

 great forest belt of 

 Mount Shasta, the 



/4.380 



! 3.000' 



Shasta Valley 



3,SOO' 



iGtmE 10.— Tree zones of Moiint Shasta, CaL a, Transition zone, 

 yellow pine {Finus ponderosa), sugar pine {Pinus larnbertiana) ,^nd 

 many others; 5, Canadian zone, Shasta fir (^bzVss^a^fcttsw); c,Hud- 

 sonian zone, white-barked pine (PinM5 albicaulU); d, alpine zone, 

 HuUea nana, extending up to 11,300 feet; e^ zone above plant growth. 

 The highest plants found are the Sierra alpine draba {Bmhahrtwtvi) 

 and PoUmoniujn pulcheUum, which occur at 13,000 feet. 



which 



moisture 



tree 



Merriam are shown in simnhfied dia£rram 



Lgure 



limit 



of 13;000 feet. 



hawks 



summit may 



manz 



nit a 



gaining on the underbrush in the struggle for existen 



rs of Mount Shasta are smaller than those of Moi 



and the charming upland meadows of the northern mount 



are entirely lacking here. 



smnmi t 



from 



considered 

 activity. 



4 r 



Althou 



o 



sulph 



