21 



900' 

 800 

 700 

 600 



O 500 



s 



£ 400 



< 300 



PREIMPOUNDMENT 



■h-t-H 



, ' ' c ' 



ON0J F MAMJ j A i 



POSTIMPOUNDMENT 



O N J F M * 



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). 



