SHASTA ROUTE SEATTLE TO SAN FRANCISCO. 



27 



ommo^ 



during that year. 



streams 



Wasliingtoiij 1,072 power 



most 



.ble fisheries in the world, except only the 03'stcr 

 and herring fisheries, are those supported hy the salmon. Of the 

 sahnon fisheries by far the largest are those of the Pacific coast of 

 North America. Columbia Kiver is justly celebrated as having 

 afforded more salmon than any other river in the world, and Astoria 

 is the chief center of the industry. 



In early days the salmon were merely dried bj 

 1833 they were first salted in old rum kesrs. 



Sacramento River, in 



he Indians. About 

 In 1864 the canning 



Columb 



The 



fish are caught in nets of various kinds, but also, and most effectively, 

 in the salmon wheel, which may be seen at many points along the 

 shores of the Columbia. By this device, which is kept in motion 



a tank . 



stream, the fish are automatically scooped up and thrown 



From Vancouver the Columb 



mile in leng 



The depth of the river here is 29 feet. Th 



present courtse before the 



range 

 channel bv ' 



■was 



ing down its bed as rapidly on the whole 

 as the mountains rose. The larerer trihu- 



Three 



have been sug- 



gested for the occurrence of the obstruc- 



wn 



carv^ 



and 



nu 



river (PL VIII). The smaller strt 

 however, have been unable to keep pace 

 with the main stream in lowering their 

 channels, and reach the river by plui]g- 

 ing over the cliffs as falls (PI. IX). Tribu- 

 tary valleys perched on the sides of a 

 main stream valley in this way are called 

 "hanging valleys." 



At Cascade Locks, in the very axis of 

 die Cascade Range, the river has been 

 unable to maintain a uniform grade and 

 falls 50 feet in a series of rapids to the tidal 

 portion of the stream. Above the cas- 

 cades the river is ponded, as if the ob- 

 struction over which it falls were acting as 

 a dam. At one time the Dondin? 



Range 



ig of the river above them. One 

 is that it represents a hump that has been 

 produced across the river channel by the 

 continued slow uplift of the Cascade 



It is supposed, in accordance 

 with this view, that the uplift of the range 

 at this place has proceeded a little faster 

 than the river could cut down its bed. 

 Another and more probable explanation, 

 in view of the localized character of the 

 obstruction, is that it is due to faulting — 





shown 



miles 



that is, to movement along a crack in the 

 rocks that runs approximately at right 

 angles with the course of tlie river, the 

 formation of the crack being followed by 

 a slipping of the rocks along it in such a 

 way that the country east of it has sunk 

 a little or the country west of it haa risen 



a little. 



and 



mass 



cascades, of trees belonging to species now 

 living that have been killed by the water 

 and partly buried in silts (PL X, A, p. 28) 

 containins: their fo^ilized leavfia. 



slid into the river from the cliffs and thus 



made a dam w 

 washed away, 

 has been done 



Not enough geolc^ic work 



which explanation is the true one. 



