LIST OF FIGURES 



FIGURE 1. Average monthly discharges (cfs) + 1 standard 



deviation in the Beaverhead River at the U.S.G.S. 

 gage at Barretts before impoundment (1950-63 water 

 years) and after impoundment (1965-75 water years) . 



FIGURE 2. Average monthly discharges (cfs) + 1 standard 



deviation in the Beaverhead River at the U.S.G.S. 

 gage near Twin Bridges before impoundment (1951-63 

 water years) and after impoundment (1965-75 water 

 years) 



FIGURE 3. Mean daily water temperatures at three stations on 

 the Beaverhead and Red Rock Rivers, 1971-72 



FIGURE 4. Map of the Beaverhead River showing the approximate 

 location of the 9 study sections 



FIGURE 5. Spring estimates of numbers (N/6566 ft) and biomass 

 (lbs/6455 ft) with 80% confidence intervals of age II 

 and older brown trout in the Hildreth Section of the 

 Beaverhead River between 1967 and 1976 



FIGURE 6. Relationships between the fall estimates of numbers 

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

 numbers of age II and age III brown trout of the same 

 year class in succeeding springs in the Hildreth 

 Section of the Beaverhead River 



Page 

 21 



22 

 23 



27 



33 

 35 



FIGURE 7. Average daily flows (cfs) during the 1964 through 1973 

 spawning periods (September 15 - October 31) of 

 brown trout in the Hildreth Section of the Beaverhead 

 River. Estimated number of age I brown trout (N/6455 

 ft) two years later is under each plot 37 



FIGURE 8. Relationship between the log variance of the average 

 daily flows (cfs) during the brown trout spawning 

 period (September 15 - October 31) and the estimated 

 number of age I brown trout two years later in the 

 Hildreth Section of the Beaverhead River 79 



FIGURE 9. Fall estimates of numbers (N/6455 ft) and biomass 



(lbs/6455 ft) with 80% confidence intervals of age I 



and older rainbow trout in the Hildreth Section of 



the Beaverhead River between 1966 and 1975 39 



