Da Hinggan Range

Da Hinggan Range, major mountain system located in the northeastern section of the Inner Mongolia Autonomous Region, northeastern China. The range extends some 750 miles (1,200 km) from north to south and constitutes the divide between the flat lowlands of the Northeast (Manchurian) Plain to the east and the high Mongolian Plateau to the west. The Da Hinggan Range is bounded on the south by the Xar Moron River and on the north by the Amur River. The range is an important watershed between the Liao, Sungari (Songhua), and Nen (Nonni) river systems of the Northeast Plain to the east and the headwaters of the Amur River and its tributaries to the northwest. The western slopes of the southern section of the range drain into the Mongolian Plateau.

The Da Hinggan Range has an average elevation from 3,950 to 4,250 feet (1,200 to 1,300 metres), the highest peak reaching 6,673 feet (2,035 metres). The range is much broader in the north (190 miles [306 km]) than it is in the south (60 miles [97 km]). It was formed during the Jurassic Period (roughly 200 to 145 million years ago), and it is essentially a tilted fault block; its ancient fault line forms its eastern edge, facing the Northeast Plain. The ranges are markedly asymmetrical, with a sharp eastern face and a more gentle western slope down to the Mongolian Plateau, which at that point lies at an elevation of 2,600 to 3,300 feet (790 to 1,000 metres). The eastern slopes are more heavily dissected by the numerous tributaries of the Nen and Sungari rivers, but generally the mountains are rounded with flat peaks. The ranges are composed largely of igneous rocks (i.e., formed through the solidification of magma).

The mountains form an important climatic divide. They take most of the precipitation from the southeasterly winds and produce a comparatively wet climate (precipitation exceeds 20 inches [500 mm] annually) that contrasts sharply with the arid region to the west. The northern section of the mountains is the coldest part of eastern China, with extremely severe winters (mean temperature −18 °F [−28 °C]) and with large areas under permafrost. This region is covered by forests of larch, birch, aspen, and pine, with shrub cover on the highest elevations. It is rich in wildlife, including deer, elk, marten, hare, and many other fur-bearing animals. The central and southern sections of the range, however, are considerably warmer and drier than in the north, with January temperatures of about −5 °F (−21 °C), annual precipitation of 10–12 inches (250–300 mm), and comparatively light snowfalls. The coniferous forests of the north gradually give way in the south to broad-leaved forests and then to patches of grassland interspersed with woodland. In the south the forests cover the higher ground above 5,000 feet (1,500 metres), while the greater part of the area is covered with tall grassland. In May 1987 a devastating fire swept the Da Hinggan forests, destroying perhaps 4,000 square miles (10,000 square km) of timber; it became known as the Black Dragon Fire, for the Heilong Jiang (“Black Dragon River”; i.e., the Amur) that flows through the area.

The Da Hinggan region was to a large extent unexplored until the 20th century. The exploitation of the northern part of the region began with the construction early in the 20th century of the first railway across the mountains—the Chinese Eastern Railroad from Qiqihar in Heilongjiang province, to Manzhouli, north of Lake Hulun, in northeastern Inner Mongolia near the border with Russia. During the Japanese occupation of Northeast China (Manchuria; 1931–45), a number of railways were constructed into the mountains north and south of this line in order to extract lumber, the most important being those running into the area north of Tulihe (Tol Gol). These lines were later extended eastward into the Yilehuli Mountains, which strike east and west and join the Da Hinggan Range to the Xiao Hinggan Range. Farther south a more recent line follows the Tao’er River valley northwest from Baicheng in Jilin province to Suolun (Solon) and the hot springs at Arxan in Inner Mongolia.

Much of the area is inhabited by peoples speaking Mongol and, in the north, Manchu-Tungus languages, such as the Orochon and Evenk. Logging continues to be the major economic activity.