LIST OF FIGURES 



Page 



FIGURE 10. Relationship between the fall estimates of numbers 



(N/6455 ft) of age I rainbow trout and the estimated 

 numbers of age II rainbow trout of the same year class 

 in the following fall in the Hildreth Section of the 

 Beaverhead River 41 



FIGURE 11. Average daily flows (cfs) during the 1965 through 1974 

 spawning periods (March 1 - April 30) of rainbow 

 trout in the Hildreth Section of the Beaverhead River. 

 Estimated number of age I rainbow trout (N/6455 ft) 

 18 months later is under each plot 43 



FIGURE 12. Relationship between the annual rates of population 

 decrease (%) of age III and older rainbow trout and 

 mean nonirrigation flows (cfs) in the Hildreth Section 

 of the Beaverhead River 51 



FIGURE 13. Relationship between the estimated numbers (N/6455 ft) 

 and the mean weights (lbs) of age II brown trout during 

 the spring in the Hildreth Section of the Beaverhead 

 River 54 



FIGURE 14. Mean weights (lbs) of age II brown trout in a series 

 of study sections in the Beaverhead River in spring, 

 1975 and spring, 1976 58 



FIGURE 15. Estimated numbers (N/1000 ft) of age II and older 



brown, rainbow, and total trout in a series of study 

 sections in the Beaverhead River in spring, 1975 and 

 spring, 1976 60 



FIGURE 16. Estimated biomass (lbs/1000 ft) of age II and older 

 brown, rainbow, and total trout in a series of study 

 sections in the Beaverhead River in spring, 1975 and 

 spring, 1976 61 



FIGURE 17. Mean values of physical and hydraulic characteristics 

 at various flows (cfs) in percent of the mean values 

 at 1000 cfs for 20 cross sections in the Hildreth 

 Section of the Beaverhead River 68 



FIGURE 18. Relationship between the annual rates of population 

 decrease (%) of age III and older rainbow trout and 

 the number of average daily flows < 150 cfs between 

 successive fall population estimates 72 



