LAKES OF THE LAHONTAls^ BASIN. 



57 



a few miles north of Anaho Island where the water is 361 feet deep over a 

 very considerable area; showing that the bottom in this portion is a nearly 

 uniform plain. As the Lahontan beach is 525 feet above the 1882 level of 

 Pyramid Lake, the former lake had a depth of 886 feet, without consider- 

 ing, however, the amount of sedimentation that has since taken place. This 

 was the deepest point in Lake Lahontan. 



Pyramid Lake is without outlet. It receives almost its entire supply 

 from the Truckee River, which enters it at its southern end. During the 

 rainy season the surrounding mountains send down some tribute, supplied 

 principally by two small brooks from the western side of the valley, which 

 are living streams for a portion of the year; but the supply from these 

 sources is extremely small. As nearly all of the fresh water entering the 

 lake is delivered at its southern end the lake varies in salinity as one follows 

 it northward. Near the mouth of the Truckee River the waters are suffi- 

 ciently fi'esh to be used for camp purposes ; at the northern end it is far too 

 saline and alkaline for human use, but may be drunk by animals without 

 injury. The waters of Pyramid Lake from two localities and at different 

 depths have been analyzed by Prof F. W. Clarke, who reports their com- 

 position as follows : 



Water of Pyramid Lake collected in August, 18S2, at b, south of Anaho Inland {see Plate IX). 



* 99.23 per cent, accounted for in the sample fi om 1 foot below surface, and 99.19 per cent, in remaining sample. 



