The deep blue waters of Lake Issyk-Kul’, one of the largest mountain lakes in the world, and the snow-covered Tien Shan are visible in this high-oblique, northeast-looking photograph. The brackish lake, with no natural outlet, is surrounded on two sides by Tien Shan peaks 13 000 to 18 000 feet (4000 to 5500 meters) high. The lake, at an elevation of 5300 feet (1600 meters) above sea level, is 115 miles (185 kilometers) long, 38 miles (60 kilometers) wide, and covers 2400 square miles (6200 square kilometers). Because the lake, the deepest part of which is 2300 feet (700 meters), is ice free during the cold Siberian winter, it is home to some species of fish. During the middle spring months, farming families cross the Tien Shan from the north to live on the shores of the lake during the late spring, summer, and early fall. The abundance of snowmelt for irrigation and the long sunshine-filled days allow these summer visitors to produce crops in fertile soil near the shoreline. During the middle fall months before the onslaught of heavy winter snows, the visitors recross the Tien Shan to their winter homes in the valley north of the range. Besides receiving water from numerous small streams and creeks, Lake Issyk-Kul’ occasionally receives water from the Chu River near its west end (barely visible in the photograph). Also shown in the photograph are the Ili River Valley and the turquoise Kapchagayskoye Vdkhr Reservoir northeast of Issyk-Kul’, the snow-covered Dzhungarskiy Alatau Mountains northeast of the reservoir, the sandy Sary-Ishikotrau Desert northwest of the reservoir, and partially ice-covered Lake Balkhash north of the desert.