met, the board may extend, revoke, or modify the 



reservation. 



A major objective of this report is to provide information for 

 this review process. 



The two major species addressed in this report are sauger 

 ( Stizostedion canadense) and walleye f S. vitreum) . This study 

 builds upon ground work laid by Peterman and Haddix (1975), Haddix 

 and Estes (1976) and Rehwinkel (1978) . Much unpublished data from 

 the Tongue and Powder rivers collected by Al Elser (Fisheries 

 Manager, Montana Dept. Fish, Wildlife and Parks) was also 

 incorporated into this report. 



DESCRIPTION OF STUDY AREA 



The Yellowstone River drainage contains approximately 182,336 

 km , 92,981 of which lie in Montana (Figure 1). It originates in 

 the mountains of northwestern Wyoming and flows in a general 

 northeasterly direction to its confluence with the Missouri River 

 in North Dakota, 1,091 km downstream. Approximately 885 km of the 

 Yellowstone River are in Montana. Average gradient is 2.44 m/km, 

 1.53 m/km, and 0.53 m/km for the upper, middle, and lower reaches, 

 respectively (Peterman and Haddix 1975 and Haddix and Estes 1976) . 

 Mean annual discharge based on a minimum of 51 years of data was 

 (107, 200, 329, and 372 m3/s (3,773, 7,043, 11,605, 13,149 cfs) at 

 Livingston, Billings, Miles City, and Sidney, respectively (U.S. 

 Geological Survey 1978) . Turbidity is seasonally high in the lower 

 river. Based on 14 samples taken by the U.S. Geological Survey 

 from March through September 1975, turbidity averaged 83, 110, and 



