ILLUSTRATIONS 



FIGURE page 



1. Chart of Trinity River Watershed 3 



2. Average monthly flow of Trinity River at Lewis ton 



during water years 1928-1942 7 



3* Average monthly discharge of Trinity River at three 



points in the drainage. Water years 1932-1939 8 



4* Trinity River water temperatures recorded at 

 Lewiston during the period; November 1942 

 through July 1946 11 



5« Numbers of adult king salmon passing through the 



Lewiston weir in 1942, 1944, 1946 and 1946, Trinity 



River 24 



6* Seaward migration of young king salmon in Ti*inity 



River at Lewiston. ••.•.•••• 29 



?• Length-frequency distribution of male and female king 



salmon from two different sections of Trinity River. • 37 



8, Downstream migration of steelhead trout in Trinity 



River at Lewiston* ••••••••••• •• 41 



9, Average lengths of steelhead trout young taken in 



fyke nets from Trinity River at Lewiston, arranged 

 according to brood years and time of capture* * * * * 44 



10* Number of salmon nests in Trinity River between 



Lewiston and North Fork as determined at two different 

 river flows* •*• •••••••** 5S 



11* Number of salmon nests in Trinity River between Lewiston 

 and North Fork, as related to a constant change in 

 availability of gravel at various river flows* . • * • 55 



12* Recommended fixed flow schedule for Trinity River at 



Lewiston and its relation to the life history phenomena 

 of king salmon in that stream* ••**•••••*•* 59 



13* The effect of a fixed flow schedule for fish at Lewiston 

 on the discharge of TJrinity River at various points 

 downstream* •••.•••••••****••*••• 61 



