well defined (Figure 5 and !P5ible 9). The spring migration passes 

 Lewiston during June and July, the 8\anmer migration during August 

 and September, and the fall migration during October and November* 



Counts of migrating adult salmon began early enough to include 

 spring-run fish in 2 of the 2 l/2 years of observations* June and 

 July ooiints in 1945 totaled 25 fish* The total count for the same 

 months, plus the first 10 days in August, amounted to 274 salmon in 

 1946* Ttie ran in 1946 was large enough to demonstrate trends and 

 limits* It began on June 28, increased rapidly to a peak on July 4, 

 tapei-ed off very gradually through July, and practically ceased by 

 the 5th of August* The spring-run segnent nearly failed in 1945* 

 The weir at Lewiston began operations June 6, but the first salmon 

 to pass it did not arrive until June 22* In the period June 28 

 through July 16, all but two of the 25 fish passed the weir No 

 other fish were counted until August 2* 



Spring-rxin salmon are very delibeirate in their migratory habits* 

 They travel fast and do not hesitate to fight any obstacle encountered* 

 Their greatest movement through the counting weir took place during the 

 two hours following sunset, although some migration continued day and 

 night. They are in excellent condition, as is shown by their visceral 

 fat, silvery bodies, and very red flesh. In s<ane years this run is 

 hardly noticeable in Trinity River because of its relatively small sise 

 and the fact that the salmon in it rarely strike at a fisherman's lure* 

 Upon reaching deeper holes between Lewiston and Trinity Center, these 

 fish stop migrating and remain in a semi-quiescent state until they 

 spawn early in October. 



The so-called summer run was much more numerous and distinct than 

 the spring xnin in both 1944 and 1946* Weir operation began August 4, 

 1944, and on that date 3 fish passed the gates* Salmon arrived at the 

 weir in erratic but gradually increasing nvonbers throughout the remainder 

 of the month* The greatest daily count was made on September 2, after 

 which the migration dwindled to practically nothing* The total number 

 of salmon involved in this run was 801* In 1945 the summer run began 

 passing the weir on August 16* It increased in the same erratic fashion 

 as did the 1944 run until the greatest daily count was made on September 4* 

 Unlike the 1944 migration, movement through the weir gates after the peak 

 day was sustained until the middle of September before a marked reduction 

 occurred* Migration virtually ceased by the end of September. The 1946 

 summer run consisted of 873 individuals* 



The STxmner king salmon are slow and rather cautious In their 

 migratory habits* They are qfuite wary of any obstruction or disturbance, 

 and their greatest movement at Lewiston took place in the four hours 

 following sunset. Little, if any, migratory movement was observed daring 

 daylight houirs* Periodic fluctuations in daily counts of these fish appear 

 to be related to changes in water temperature* At Lewiston, there was gen- 



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