The Greater Khingan Mountains, also known as the West Khingan Mountains, is an important mountain range in northeast China, lying in the northeast of Inner Mongolia Autonomous Region, between the Inner Mongolia Plateau and the Northeast China Plain. The northeast and north-northeast trending mountain range stretches from the banks of the Heilong River in the north to the upper reaches of the Xar Moron River in the south. It is about 1,200 km in length and 200–300 km in width. Its average elevation is 1,100–1,400 m above sea level. The highest peak of the mountain range is Mount Huanggangliang, at 2,029 m above sea level. The Greater Khingan Mountains is an asymmetrical range, high in the northwest and low in the southeast, with a gentle western slope bordering the Mongolian Plateau and a steep eastern slope abutting the Northeast China Plain. The mountain range is wide in the north and narrow in the south.