The remainder of the province consisted of a fertile steppe in the north-east (Sergiopol), and vast uninhabitable sand-steppes on the south of Lake Balkhash. Southwards from these at the foot of the mountains and at the entrance to the valleys, there are rich areas of fertile land. Climate The climate in Zhetysu is thoroughly continental. In the Balkhash steppes the winter is very cold. The lake freezes every year, with temperatures falling to −11 °C (13 °F). In the Ala-kul steppes the winds blow away the snow. The passage from winter to spring is very abrupt, and the steppes are rapidly clothed with vegetation, which, however, is soon scorched by the sun. Average temperatures at Almaty (733 m, 2,405 ft high) are: for the year , for January −8 °C (17 °F), for July 23 °C (74 °F). At Przhevalsk (1,660 m, 5,450 ft): for the year 2.5 °C (36.5 °F), for January −5 °C (23 °F), for July 17 °C (63 °F); still higher in the mountains, at Naryn (2,100 m, 6,900 ft), the average temperature for the year is only 6.5 °C (43.7 °F), for January −17 °C (1.4 °F), for July 18 °C (64.4 °F). Bodies of water The most important river is the Ili, which enters Zhetysu from the Tian Shan mountains of China's Ili Kazakh Autonomous Prefecture in northern Xinjiang, and drains it for 250 km before it enters Lake Balkhash. The Chu River also rises in the Tian Shan mountains and flows north-westwards through the former Akmolinsk province of the Governor-Generalship of the Steppes. The Naryn River flows south-westwards along a longitudinal valley of the Tian Shan, and enters the Fergana Valley to join the Syr Darya. The major lakes of the area include Lake Balkhas (or Denghiz) and Lake Ala Kul, which was connected with Balkash in the post-Pliocene period but now stands some hundred feet higher, connected by a chain of smaller lakes with Sissyk Kul, Lake Issyk-Kul, and the alpine lakes of Son-Kul and Chatyr-Kul. Population The population was estimated in 1906 as 1,080,700. Kazakhs formed 76% of the population, Russians 14%, Taranchi (Uyghurs) 5.7%. History and administration History of the central steppe has an outline history with links to the many peoples who lived in this area. In the VI-III vv. BC. e. the Iranian Sakas (Scythians) established their first state, whose center was in Zhetysu. In the mid 6th