During 7 hours of the day, water temperatures were ahove 80°?., while 

 during 11 hours, temperatures were below 75*'F, Between 9 a.m. and 

 4 p.m., the river temperature rose 11.5 degrees, and between 6 p.m. 

 and midnight it fell 7.5 degrees. 



On July 4, 1945, a recording thermcaneter was installed at 

 Junction City, some 28 miles down river from Lewiston, to determine the 

 warming effect of hot summer weather on the river between these two points. 

 The maximxan., minimum, and average daily water temperatures recorded at 

 this station are given in Tables 6 and 7, A maximvua temperature of 

 85*'F„was recorded at that station on July 27, 1945, the same day the 

 peak temperature of 83°F.»was recorded at Lewiston. The hottest days 

 of the summer were July 26 and 27, when a maximum air temperature of 

 108OF., was recorded at Lewiston on both days. The river temperature 

 reached or exceeded SO*'?., on 32 days in the suraner months at Jvinction 

 City. During July and August, maximum water temperatures at Junction 

 City were one or two degrees higher than Lewiston water temperatures 

 for the oorresponding day. Temperature records at Junction City during 

 1946 were too incomplete for analysis. 



EXISTIHG BIOLOGICAL CONDITIOSS 



Non-game Fishes 



The Klamath black dace, Rhiniohtys os cuius klamathensis (Everaann 

 and Meek), and the fine-scaled Klamath River sucker, Catostomue rimi cuius 

 Gilbert and Snyder, are the only coarse fish taken during this study 

 which are known to spend their entire life cycle in the Trinity River. 

 Both of these species occur cOTimonly throughout the drainage. 



The Klamath black ciice is the most numerous and ubiquitous species 

 found in the Trinity River. It inhabits all stream sections except the 

 headwaters of some tributaries. The d&ce is a small fish in the Trinity; 

 the largest individuals seldom exceed a fork-tail length of 3.1 inches 

 (80 millimeters). During the summer low-water period, Klamath black dace 

 are seen in very large numbers in pools along the river. They are almost 



10 



