106 
BULLETIN OF THE BUREAU OF FISHERIES. 
as 64.4 km. 2 (25 square miles), and its drainage basin adds but 15.5 km. 2 (6 square 
miles) to this. 
The elevation of the surface of the lake (U. S. Geological Survey map, 1911) is 
given as 1,883 m. (6,177 feet). The elevation of the rim varies from 2,073 to over 
2,498 m. (6,800 to 8,200 feet). The precipitation at the lake is said to be from 
152 to 177 cm. (60 to 70 inches), mostly in the form of snow. The lake has no 
inlets and no known outlets, and still the water is soft. Total residue is 80 parts 
per million. Walton Van Winkle and N. M. Finkbinder (1913) of the U. S. Geolog- 
ical Survey, Salem, Oreg., have published an analysis of the water, which varies 
but little from many of the soft-water lakes, from which the following is quoted: 
That the analysis really shows concentration almost identical with that of other surface waters of 
the region is explained, however, by the fact that no sedimentary materials are exposed, the andesites, 
dacites, and basalts forming the basin of the lake, being nearly insoluble in the cold water, and, there- 
fore, incapable of rapidly increasing its content of mineral matter. Concentration of 'chlorides is great 
as compared with that of other materials, an indication of the concentrated character of the water. As 
the published analyses of rocks indicate that almost no chloride exists in these formations, it is possible 
that the high percentage of that radicle in the water is due almost entirely to accumulated “cyclic” 
chlorine precipitated with the rain and snow. The unexpectedly high percentage of sulphates is 
possibly caused by solution of sulphur that remained in the bottom of the caldera in a more or less 
oxidized condition at the cessation of active volcanism. No other features of the analysis seem unusual, 
when it is compared with the accompanying analyses of waters collected from Wood and Rogue Rivers 
in the same season. 
The water of Crater Lake is a deep clear blue. The 12 cm. Secchi disk was 
read at 25 m. August 1, 1913, and 27 m. September 5, 1913, and Differ (1897) 
states that “a white dinner plate 10 inches in diameter may be seen at a depth of 
nearly 100 feet.” This agrees fairly well with the above results. 
The greatest depth recorded is 608.4 m. (1,996 feet). On our first trip we 
found bottom at 602 m. with our sample line and the second trip at 600 m. Since 
the line had not been corrected for this depth and weight, we were probably nearer 
the deepest water than these results indicate. 
Originally there were no fish in Crater Lake. W. G. Steel (1907), S. S. Nico- 
line, and E. D. Dewart carried rainbow-trout minnows from Gordans ranch 41 
miles to the lake. Thirty-seven were placed in the lake September 1, 1888. The 
first trout were caught in 1901. Others have been planted since that date, and the 
lake now (1913) offers some of the best trout fishing we have ever enjoyed. 
TEMPERATURES. 
The low surface temperature (11.7 to 12.1° C.) of Crater Lake is readily 
accounted for when we consider its altitude and latitude, together with the facts 
that it occupies a deep basin that collects large quantities of snow during the winter 
and that the summer heat is not sufficient to completely melt this snow. On 
August 1, 1913, large banks of snow were very plentiful from the top of the rim 
to the surface of the lake. On September 1 much snow could still be found in the 
shady places. The small amount of warm weather at this place is best shown by 
the facts that in the same year the rim was first reached on foot July 4 and that 
the first autos arrived on July 20 by a road shovelled through the snow. When 
we left on September 5 it was freezing at night on the rim, and snow was expected 
