From hourly counts at Deer Greek, it has been found that there is 

 no certain time during the day or night when a heavy migration can be 

 expected. In general, however, the following statements concerning the 

 movement of salmon in Deer Creek have been found to be true; 



lo After a period of clear weather, a rain sufficient to cause a 

 slight discoloration of the water \Till bring up a surge of fish. 



2. At the close of a period in which the weather has been clear 

 and the water relatively cocl, sudden increases in water temperature 

 to about ?5° F. will cause an upsurge of fish, 



3» After maximum water temperatures approaching 80° F. become 

 common, the fish rest in deep pools throughout the day and move 

 upstream only at night, 



U. Water temperatures of 8l° to 82° F. are lethal to adult king 

 salmon. 



5. Fingerling salmon in Deer Creek have remained alive in water of 

 a temperature that is lethal to adults. 



Distribution of Adult Salmon 



Beginning in 19Ul, observations were made each year during the 

 summer months along that portion of Deer Creek upstream from the mouth 

 of the canyon to determine the distribution of adult spring-run salmon. 

 Lethal water temperatures in the creek below the mouth of the canyon 

 eliminate this lower section of the creek as a summer or prespawning- 

 period holding area. Although the density of the population varied, it 

 was always found that the salmon were well distributed throughout the 

 stream section available to them. This distribution is important because 

 it allows for the best possible use of the spawning gravels and prevents 

 overcrowding on any particular area. 



The distribution pattern of the fall-run salmon in Deer Creek is 

 different from that of the spring-run, and is controlled primarily by 

 water flows during October and November. With normal flows present, that 

 is, enough water to enable the fall salmon to ascend the ladders over 

 Stanford-Vina Dam, the bulk of the run spawns in the section of the creek 

 betv;een the canyon mouth and the Sacramento River. When lower-than- 

 usual flo^iTS are present, the fall run is limited generally to that sec- 

 tion of the streara below the Stanford-Vina Irrigation Dar.i. The fall-run 

 salmon spawn soon after entering the creek from the Sacramento River and 

 do not engage in any extensive holding or ripening period. 



