The length of the lake approaches 65 mi (105 km), the width 4.... lake shore

The length of the lake approaches 65 mi (105 km), the width 40 mi; the surface of the lake is approximately 2,300 sq mi (about 6,000 sq km) in area in years when the water level is high, and about 1,600 sq mi (4,200 sq km) in area when the water level is low. The lake that formed in the depression originally drained into the Ma-ch'u Ho, but the rise of the basin's mountainous frame made this impossible. Melting waters from ancient glaciers thus accumulated and formed a big, deep lake in the late Pleistocene (at least 10,000 years ago). The depression in which the lake is set is a plain more than 10,500 ft high. In the south the depression is bordered by the Nan Koko Nor Shan (South Koko Nor Mountains), which form a narrow chain connecting with distinct peaks. The shores of the Koko Nor open out gently; the delta of the Pu-k'o Ho (Pu-k'o River) empties into the western part of the lake. Along the shores woods spread in terraces, the highest of which extends up over the lake t! o a height of 160 ft. On the eastern shore there are many small, isolated lakes and a rising, wooded shore area. Numerous sandy islands dot the lake; the largest has a length of 5,410 feet and a width of more than 1,000 feet. On the southwest shore of the lake and on the slopes of the Nan Koko Nor Shan there is an annual precipitation of 10 to 12 in. During the summer, water in the lake warms to 6468 F (1820 C). lake shore