PYRAMID LAKE, NEVADA. 



509 



travel for days over the desert with the old wave-cut benches circling 

 the mountains far above him. 



Pyramid Lake occupies the deepest of the basins of Lake Lahonton. 

 It has a depth now of about 360 feet, but the waters of the ancient lake 

 rose 500 feet higher, making its greatest depth at the time of maximum 

 expansion nearly 1,000 feet. Pyramid Lake has a length of thirty 

 miles and a maximum width of ten miles. It is fed by the Truckee 

 Eiver, which has its source in Lake Tahoe in the high Sierras. The 

 lake is, of course, alkaline, as are all the lakes of the Great Basin, hut 

 the water is not as strongly impregnated as some of them. It is well 

 supplied with large trout, as well as several other kinds of fish. The 

 water is unfit for people to drink, although it answers for stock. 



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Fig. 4. Tcfa Deposits, North End of Pyramid Lake. 



High mountains come down to the lake, leaving in places scarcely 

 room for a road, and although the waters are quiet as a rule, yet 

 they are subject to sudden and violent storms. 



At many points within the basin of the former lake, Lahonton, there 

 are strange-appearing deposits of calcareous tufa, either encrusting the 

 rocks or rising in curious and fantastic towers and domes. The waters 

 of the lake were richly impregnated with calcium carbonate, derived in 

 part from the incoming streams, but more largely probably from cal- 

 careous springs. As the lake waters receded, the salts in solution be- 

 came more concentrated and soon began to form chemical precipi- 

 tates upon projecting rocky points. In the port ion of the basin now oc- 



