Ward. — Migration of the Sockeye Salmon 401 



below that of the stream above, and it was in this section that 

 the fish were most abundant and most actively engaged in nest 

 building, as well as furthest advanced in coloring and conse- 

 quently nearest the spawning period. Above the point where 

 the stream emerges from the marshy region there was de- 

 tected little or no cold water seepage from the bank, and con- 

 sequently the temperature of the water was distinctly higher. 

 The amount of water added to the stream in the way indi- 

 cated must have been considerable, for the volume of Clear 

 Creek where it flows under the trestle is apparently at least 

 twice as great as where it emerges from the swampy area, a 

 mile or two above the trestle. These facts serve to explain 

 that the situation in the stream accords with the movement 

 of the salmon, which kept themselves in the cooler part of the 

 creek and spawned in the section where a steady inflow of 

 cold water gave the minimum temperatures found in the 

 stream. 



Although this spring-fed region is the coldest area of the 

 water during the summer season, it will evidently be the most 

 stable and hence the warmest during the winter. According to 

 the testimony of men familiar with the region, this part of the 

 stream remains open until very late in the year and does not 

 freeze over until long after other waters are solidly covered 

 with ice. Evidently also the gravels in the vicinity of springs 

 are least likely to become frozen and hence afford greatest pro- 

 tection to the developing eggs. Jordan and Evermann ( 1904) 

 state that freezing kills the eggs, and if any areas in this region 

 avoid that condition in the long, severe winter, it must be the 

 gravel beds in which springs emerge. 



On the west side of the Copper River valley at a distance 

 of 20 or 30 miles from the stream and about 150 miles from 

 the mouth of the Copper River are three large lakes that have 

 been said to be important spawning grounds for the red sal- 

 mon. These three are lakes Tonsina, Klutina, and Tazlina. 

 Lake Tonsina is the farthest south and the smallest. Lake 

 Tazlina lies 50 miles northwest of it and is the largest. Lake 



