500 



450 



400 



350 



I 



^300 

 w 



Q 



Z 

 < 



° 250 



200 



< 



o 

 o 



2 

 X 



o 



150 



100 



50 



TOTAL SPRING 

 SPRING RUN 

 SUMMER RUN 



SUMMER RUN 



X 



_1_ 



1939 41 



J L 



i . I L 



J L 



^3 ^5 



J I L 



'47 



49 



■51 '53 



YEAR 



'55 



'57 



'59 



'61 



'63 



'65 



Figure 2 — Runs of spring and summer Chinook salmon in the Columbia River, 1939-66. Runs exclude catches by 

 the sport fishery in the ocean and lower Columbia River, landings by the offshore troll fishery, and the escape- 

 ment to tributary streams entering the Columbia River below Bonneville Dam with theexceptlonof the Willamette 

 River run. The straight lines have been derived from the least squares method. 



14 



