stable flows (Figure A-28, A-29, A-30, A-31, and A-32) . Mean April 



flows ranged from 583 to 1073 cfs during 1976 to 1979 (Table 23) . 



The mean April discharge during 1980, 270 cfs, was only lower once 



from 1938 to 1980. This occurred in 1961 when the mean April 



discharge was 109 cfs. Although sauger reproduction was documented 



in the Powder River during 1980, it is not known how low flows 



affected total larval sauger production as no previous collections 



are available for comparison. 



Larval sauger were collected in the Powder River from May 2 to 



12, 1980 (Table 25); a range of 17 to 27 days after the maximum 



number of sauger were captured. Continued work is necessary to 



quantify critical low flows and optimum flows for sauger 



reproduction in the Powder River. 



Table 25. Number of larval sauger collected and estimated rate of 

 drift in the Powder River near its mouth, 1979 and 1980. 



99 



