NORTHWESTERN LAKES OF THE UNITED STATES. 
99 
CRESCENT AND SUTHERLAND LAKES, WASH. 
To the south of the Strait of Juan de Fuca, in Clallam County, Wash., lie two 
interesting lakes, Crescent and Sutherland. 
Crescent Lake lies 24 km. (15 miles) west and 8 km. (5 miles) south of Port 
Angeles. It is a beautiful lake, 14.5 km. (9 miles) east and west by 2 km. (1£ 
miles) north and south, lying between the main range of the Olympic Mountains 
and the coast range at an elevation of 204 m. (670 feet) . Soundings gave a depth of 
145 m. in the center of the east bay and 75 m. in the narrows. The deepest water 
(175 m.) was located near the center of the lake, 3.25 km. (2 miles) west of the 
narrows. 
The temperature and clearness of this lake are similar to those of the very 
deep lakes, such as Chelan and Tahoe. The water is very clear, but not as clear 
as that of Tahoe and Crater lakes-. The temperature decreases gradually from 
16.4° C. at the surface to 5.6 at the bottom, with no marked thermocline. 
Crescent Lake is noted for the blueback trout ( Salmo beardsleei), which is 
caught by trolling in deep water with a heavily weighted or wire line. Speckled 
trout (Salmo crescentis ) and the long-headed trout ( Salmo bathcecetor) are found 
in this lake. Lake Sutherland contains Jordans trout (Sdlmo jordani) and the sal- 
mon trout (Salmo declivifrons) . Besides these, both lakes are said to contain 
cutthroat trout (Salmo clarkii) , and a few salmon are said to rim into each. 
Crescent is one of the deeper lakes that has a very small amount of plankton. 
A few Crustacea, however, were found at all depths, even at the bottom. 
Epischura was the only copepod noted in the plankton catches of Crescent 
Lake. It was found at all depths. A few Daphnias were found in the catch 
taken between 20 and 30 m. 
Most of the nauplii were secured in the upper 10 m. (See Table 12, p. 126.) 
The maximum number of rotifers per cubic meter of water was obtained in 
the 0-20 m. stratum. Some specimens of Dinobryon were noted in the 10-20 m. 
catch. The predominant alga was the diatom Gonatonema. 
Sutherland Lake lies 1 mile east of Crescent Lake at an elevation of 188.9 m. 
(620 feet). It is 4 km. (2.5 miles) long by 1.6 km. (1 mile) wide. It lies. at the base 
of mountains 1,000 m. high, from which it receives most of its water. Indian 
Creek is the outlet. The lake is surrounded by trees, which, with the mountains, 
protect it from the wind. The thermocline is well marked and lies between 9 and 
11 m. The oxygen decreases below the thermocline, but on August 18 there was 
still sufficient for fish life near the bottom. 
About 52,000 Crustacea per cubic meter of water were found in the surface 
stratum. The most abundant crustacean in this stratum was DiapTianosoma 
brachyurum, although large numbers of Cydops prasinus and Diaptomus tyrelli were 
present. One-fourth of the Cydops prasinus and the maximum number of Bosmina 
longirostris per cubic meter of water were in the 16-20 m. stratum. 
LAKE GOODWIN, WASH. 
The maximum number of Crustacea per cubic meter of water was found in 
Lake Goodwin in the 0-3 m. stratum. 
