section and one day on the River Bend section in 1988. Eight of 



the twelve bull trout were larger than 15 inches in length. 



Westslope cutthroat trout accounted for 2% of the trout captured 

 in the Scotty Brown section during 1988. 



Reach 5: Belmont Creek to Mouth of Blackfoot River 



(RM 21.9 to RM 0) 



Fisheries information in this reach is based on sampling of 

 the Johnsrud Section (RM 11.7 to 15.3). Population inventories 

 were not conducted during 1988 due to time constraints resulting 

 from poor electrof ishing efficiency during the late-summer and 

 fall. Fieldworker time allocated for 1988 was saved for spring 

 1989 to update fisheries information collected during the spring 

 and summer periods from 1980 to 1985. Electrof ishing surveys 

 were conducted in the Johnsrud section, and from River Bend FAS 

 to Whitaker Bridge during 1988 to compare sampling efficiency in 

 this reach to reach 4. 



Unlike the Scotty Brown section, high densities (226/1,000 

 ft) of subadult rainbow trout (4.0 to 10.9 inches) reside in the 

 Johnsrud section of reach 5 (Table 3). 



Table 



Trout population estimates for the Johnsrud section 

 of the Blackfoot River, June 1985. 



Cutthroat 6.0-14.9 



197 



50 



10 



Brown 



6.0-24.0 



115* 



90 



6* 



Bull 



6.0-34.0 



75* 



69 



4* 



* This estimate did not meet minimum requirements for an 



unbiased estimate and should be used with caution (Ricker, 

 1975 pp. 79) . 



Despite high densities of rainbow trout less than 11.0 

 inches in the Johnsrud section, there appears to be fewer than 

 expected numbers fish larger than 11.0 inches. Compared to other 

 western Montana streams, the number of rainbow trout larger than 

 14.0 inches (2.6/1,000 ft) is very low (Figure 12). 



The Johnsrud section shows signs of high losses (mortality 



26 



