downstream 4.8 km. The section near the Tongue River began 3 . 2 km 

 upstream from the mouth and extended 8 km downstream. Two sections 

 near the Powder River included one which began at the mouth and 

 extended 7.1 km upstream and another which began at the mouth and 

 extended 2.4 km downstream. The Intake study area began at the 

 irrigation diversion and extended 2 . 6 km downstream. Both sides of 

 the river were sampled in all study sections except below the mouth 

 of the Powder where only the south side was sampled (in turbid 

 effluent from the Powder) . 



To locate mainstem spawning grounds at locations other than 

 established sampling stations, two reaches of the Yellowstone River 

 from Forsyth to the mouth of the Tongue River (84 river km) and 

 from the mouth of the Tongue River to the North Dakota border (272 

 river km) , were electrof ished (Figure 3) . The first was sampled 

 during May 2-3, 1979 and the second from April 19-27, 1980. The 

 entire length of these sections were sampled (one side) when large 

 concentrations of gravid sauger were known to be present in the 

 Tongue and Powder rivers. 



To identify spawning areas for sauger in the Tongue River, the 

 reach from Twelve Mile Dam to the mouth (32 river km) was 

 electrof ished during May 9-10, 1979 (Figure 3) . Sampling occurred 

 while large concentrations of sauger were present in the Tongue 

 River. 



Unpublished electrof ishing data form the Tongue and Powder 

 rivers has been summarized and included in this report. Data from 

 the Powder River prior to 1979 was collected in a study by 



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