NORTHWESTERN LAKES OF THE UNITED STATES. 
95 
The lake is fed by a large number of inlets, practically all of which are good 
trout streams, while its .outlet, Priest River, is equally noted for its trout fishing. 
The soundings on the map (fig. 17) are given in meters at the points designated. 
These points were only roughly located from the boat. It will he noted that the 
south end of the lake is shallow, but that the north end, even through the narrows, 
continues deep. 
The scarcity of plankton accounts for the clearness of the water, the disk 
reading 13.35 m., next to Lake Chelan in this respect. The scarcity of algae is a 
noticeable feature. (See Table 12, p. 130.) Later, no doubt, there comes a "bloom” 
period, but at the time of our visit, August 17, 1911, there was no evidence of its 
approach. 
Below 50 m., the net plankton was very scarce; occasionally a 10-m. haul would 
bring up a copepod or a nauplius but no Protozoa. At this depth there was an 
abundance of oxygen, but the water was cold. No algae were found below this point. 
SILVER LAKE, WASH. 
Silver Lake belongs to the shallow lakes. The epilimnion was distinctly 
alkaline. The net plankton consisted chiefly of algae and Cladocera. Most of the 
Cladocera were immature individuals. 
SPIRIT LAKE, IDAHO. 
This lake is surrounded on all sides by hills that are wooded down to the water’s 
edge. At the upper end a small stream enters, and here there is some marshy 
ground that is inundated during high water. 
The Copepoda' showed a uniform distribution from the surface to within 5 m. 
of the bottom. The Cladocera were most numerous near the bottom in the cooler 
water. Diatoms were most abundant in the 5-10 m. stratum. 
SULLIVAN LAKE, WASH. 
Sullivan Lake lies in the northeast corner of Washington. It is 6 km. (3.7 
miles) long and 1.6 km. (1 mile) wide, extending north and south between two 
ridges of high mountains. The lake has recently been raised by a 3 m. (10 foot) 
dam and is used as a reservoir to supply power at Metaline Falls. It has an eleva- 
tion of 783.5 m. (2,570 feet). Its shores are very steep, and a large part of the lake 
is more than 50 m. deep. The deepest place, 95 m., is at the center of the lake. 
At the upper end the lake is fed by a small stream and at the lower end gives rise 
to a tributary to Sullivan Creek. 
The lake contained a few logs when we visited it, and it was reported to have 
had many more. These gave the water a brown color and probably decreased 
the disk reading. It is noted for its cutthroat-trout fishing. 
Most of the net plankton was found in the upper 20 m. Among the Crustacea 
the copepods were more abundant than the cladocerans. 
