THE KIVEB FLOODS 259 



the weather beneath thick folds of lava, just as 

 many of the rivers of Alaska lie beneath folds of 

 ice, coming to the light farther down the range in 

 large springs, while those of the high Sierra lie 

 on the surface of solid granite, exposed to every 

 change of temperature. More than ninety per 

 cent, of the water derived from the snow and ice 

 of Mount Shasta is at once absorbed and drained 

 away beneath the porous lava folds of the moun 

 tain, where mumbling and groping in the dark 

 they at length find larger fissures and tunnel-like 

 caves from which they emerge, filtered and cool, 

 in the form of large springs, some of them so large 

 they give birth to rivers that set out on their jour 

 neys beneath the sun without any visible interme 

 diate period of childhood. Thus the Shasta Eiver 

 issues from a large lake-like spring in Shasta Valley, 

 and about two thirds of the volume of the McCloud 

 Eiver gushes forth suddenly from the face of a 

 lava bluff in a roaring spring seventy-five yards 

 wide. 



These spring rivers of the north are of course 

 shorter than those of the south whose tributaries 

 extend up to the tops of the mountains. Fall 

 Eiver, an important tributary of the Pitt or Upper 

 Sacramento, is only about ten miles long, and is 

 all falls, cascades, and springs from its head to its 

 confluence with the Pitt. Bountiful springs, charm 

 ingly embowered, issue from the rocks at one end 

 of it, a snowy fall a hundred and eighty feet high 

 thunders at the other, and a rush of crystal rapids 

 sing and dance between. Of course such streams 

 are but little affected by the weather. Sheltered 



