Table 1 F_ISH_ COUNTS AT ROCK ISLAWB Q^M 1/'' 



■—— CHINOOK " ~~"~~~S"TEELHEAD BLUEBACK TOTft^L ALL 



YEAR SPRING STMMER TOTAL SPRING FALL T0T3LL TOTAL SPECIES 



TOTAL 48,fi70 82,127 126,563 12,563 31,161 

 AVERAGE 3,042 5,133 7,910 785 1,948 



* No ootints made during the first 3 weeks in June 1948 due to severe floodo The 

 arbitrary date selected to separate the spring and summer runs was July 9o A few 

 silvers have also been counted (226 in 1947) o 



Grand Coulee Dam is located approximately 63 miles above the mouth of the 

 Ok-anogan River and approximately 595 river miles above the mouth of the Colombiao 

 It first blocked fish in 1939 and water first spilled over its top in 1944o Ita 

 f»r«bay height of 290 to 325 feet above ts.ilwater provides a complete bayrior to 



