The age data, when combined with mean length of the fish in each age 

 group, can provide a rough means of cor.iparing fish growth among the different 

 Mount Haggin streams. Average lengths of brook trout by age group are pre- 

 sented in Table 9. 



Table 9. Mean brook trout length (inches) at different age groups from 

 1,000 feet study sections on Mount Haggin streams. 



Stream 



Age Group 



I 



II 



III 



IV+ 



Seymour Creek 

 Sullivan Creek 

 Twelvemile Creek 

 Slaughterhouse Creek 

 Tenmile Creek 

 Sevenmile Creek 

 Deep Creek 

 Sixmile Creek 

 Oregon Creek 

 American Creek 

 California Creek 

 Willow Creek 



2.3 



4.0 

 3.4 

 4.0 

 4.7 

 3.8 

 4.5 

 5.0 

 4.0 

 4.4 

 3.9 

 4.3 

 4.0 



5.4 

 4.7 

 5.6 

 6.4 

 5.4 

 5.8 

 6.3 

 5.3 

 5.8 

 5.3 

 5.6 

 5.4 



6.8 

 5.8 

 7.3 

 7.8 

 7.2 

 7.4 

 7.6 

 7.2 

 7.4 

 6.9 

 7.3 

 6.8 



9.2 

 8.2 

 8.9 

 9.0 

 9.2 

 9.2 

 9.9 

 8.8 

 10.3 

 9.3 

 9.1 

 8.0 



The average lengths at age of Mount Haggin brook trout varied between streams 

 and ranged from 3.4 inches in Sullivan Creek to 5.0 inches in Deep Creek at 



age I, 4.7 inches in Sullivan Creek to 6.3 

 5.8 inches in Sullivan Creek to 7.8 inches 

 III and 8.0 inches in Willow Creek to 10.3 

 and older. Mean brook trout length at age 

 4.2 inches at age I, 5.6 inches at age II, 

 inches at age IV and older. 



inches in Deep Creek at age II, 

 in Slaughterhouse Creek at age 

 inches in Oregon Creek at age IV 

 for all Mount Haggin streams was 

 7.1 inches at age III and 9.0 



Discussion 



The most widely distributed gamefish in the streams of the Mount Haggin 

 area is the brook trout. Brook trout are common to the upper Big Hole River 

 and the majority of its tributaries (MDFWP, unpublished data). Brook trout 

 were found in all of the Mount Haggin study sections and were virtually the 

 only gamefish collected in Seymour, Sullivan and Twelvemile Creeks. Brook 

 trout were introduced into the upper Big Hole River about 1929 (Liknes, 1981) 

 and have become established in most tributary streams. The second most widely 



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