Table 3. — Silver salmon counted at Rock 

 Island Dam, 1954-60 



7 14 21 28 4 II IB 25 2 9 16 23 30 6 13 20 2? 3 10 17 24 I 8 15 22 

 Moy Jun« July August September October 



Figure 4. — Weekly steelhead counts at Rock Island Dam, 

 1954-60. 



DISTRIBUTION AND COMPARATIVE 



ABUNDANCE OF SPAWNERS IN 



TRIBUTARIES 



Spawning streams were surveyed by the 

 same personnel using comparable methods 

 each year. The various streams were surveyed 

 by either walking or floating downstream in a 

 boat. On surveys the numbers of live and dead 

 salmon and number of redds were counted, 

 dead chinook salmon nneasured for length, 

 and females examined for spawning condition. 

 In 1960 the numbers of eggs retained in the 

 body were determined for all dead female 

 Chinook salmon retrieved. In some instances 

 streams were surveyed from an airplane 

 and redds counted. 



Official counts: 



Periodic counts: 



Chinock Salmon 



Complete daily coimts at 

 the three ladders. May 1 

 to end of official counts. 

 Periodic counts at dif- 

 ferent hours, after end of 

 official counting period. 



The areas within each tributary stream 

 above Rocky Reach Dam utilized by chinook 

 salnnon spawners are illustrated in figures 

 5, 6, and 7, and those of the Wenatchee 

 River system spawning areas in figure 8. 

 The distribution of salmon shown in the 

 figures is a composite of the distribution 

 observed over the 7 years of surveys. The 

 distribution of spawners within individual 

 streams varied only slightly for large and 

 small escapements of various years. Gen- 

 erally, spawning populations chose the same 

 specific areas. Minor changes in specific 

 locations of spawners have been observed 

 within these favored areas. For example, 

 in I960, in the Methow River, summer chinook 

 salmon were observed in main channel areas 

 where water velocities were greatest. In 

 1959, when higher flows prevailed during 

 the spawning period, the spawners in these 

 areas were observed closer to shore and 

 away from the high velocities in the main 

 channels of the river. 



The peak survey counts (greatest num- 

 ber counted on any one survey) and the time 

 period encompassing the peak of spawning for 

 tributaries above Rocky Reach damsite are 

 given by year in table 4; comparable data 

 for the Wenatchee River system are given 

 in table 5. For purposes of illustrating main 

 spawning areas, the streams are divided 

 into sections. The tables reveal the com- 

 parative abundance of spawners within each 



