CONTENTS 



Page 



A brief history of the Columbia River bluebackso ^ ...,,. „.o . 1 



Present status of blueback runs. ,o.....o....o.o..., 3 



Spawning surveys o- ,..■, ...o .o ,„......,.,,.,.. „ 7 



Lake Wenatchee surveys ..........<........... -o . 7 



Okanogan surveys ,,..<.<,...<...<...... ...» ...... l6 



Survival in the rearing lake ..................... 23 



Future runs and recoimnendations, ..... ......... 23 



Summary and conclusions ......... ............... 28 



Literature cited ............... ...... 29 



ILLUSTRATIONS 

 Figure Page 



1. Known blueback salmon rearing areas of the Columbia River 



River System — past and present ....•.....,.,.,,. 2 



2. Commercial catches of blueback salmon, Columbia River, 

 1889-1950. ........................... h 



3. Present known migration routes of blueback salmon, Columbia 



River System . 5 



It. Columbia River blueback salmon counts over Bonneville and 



Rock Island Dams and total run data 1938-51 8 



5. Columbia River blueback salmon counts over Bonneville and 

 Rock Island Dams and total r\m data 1938-^1 plotted by 



ii-year cycles. 9 



6. Diagrammatic map of the principle blueback salmon spawning 



areas of the Lake liTenatchee System . 10 



7. Occurrence curves from blueback spawning counts in the 



Okanogan River, 19ii7 . . lii 



8. Diagrammatic map of the principle blueback salmon 



spawning areas of the Okanogan River System. .......... I8 



9. Map of upper Okanogan region showing possible spawning 



area for blueback salmon ...........,...,,.,. 25 



