Table 10. Summary of electrof ishing survey data for a 1,000 ft section of 

 American Creek (T3N, RllW, Sec. 30C) on August 7 and Auaust 19, 

 1980. 



Species No. Captured Length Range (inches) 



Brook Trout 147 2.0 - io.2 



Rainbow Trout 8 6.4-9.2 



Rainbow X Cutthroat Hybrids 1 9.5 



Mottled Sculpin 



Standing crops of brook trout and rainbow trout in the study section 

 were estimated using a mark-recapture method (Table 11). The section supported 

 approximately 160 brook trout and 8 rainbow trout representing a combined 

 biomass of 13 lbs. Catchable fish (6 inches and larger) composed 24 percent 

 of the brook trout population. Brook trout condition (length to weight ratio) 

 was good although slightly below average when compared with other Mount Hagqin 

 streams and other streams in the upper Big Hole River drainage (MDFWP unpub- 

 lished data). 



Table 11. Estimated standing crops of brook and rainbow trout in a 1,000 foot 

 section of American Creek (T3N, RllW, Sec. 30C) on August 7, 1980. 

 Eighty percent confidence intervals are in parentheses. 



Per 1,00 ft. 

 Species Length Group (inches) Number Pounds 



Brook Trout 3.2 - 5.9 122 



6.0 - 10.2 38 



160(+24) 12(+1) 

 Rainbow Trout 6.0-9.2 8 



8(+3) l(+0) 



A brief reconnaisance of American Creek was conducted by MDFWP fisheries 

 biologists in 1976. They rated the stream as having a good fishery potential 

 for the production of catchable brook trout. 



4. FLOW RECOMMENDATIONS 



Cross-sectional data were collected for a 169 foot riffle-run sequence 

 located approximately at stream mile .2 (T3N, R12W, Sec 25D). Five cross 



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