The border starts in the west at the western tripoint with Russia in the Altai Mountains, located just 100 kilometres (62 miles) east of the China-Kazakhstan-Russia tripoint. From there it runs overland in a generally south-eastwards direction, with straight line sections predominant in the Gobi Desert section, down to the southern-most point of Mongolia just north of the 40°30 line of latitude. From there it proceeds overland in a north-eastwards direction, over to the Greater Khingan mountains near Mongolia's eastern-most point. From there the border veers to the north-west and then west, utilising the Khalkhyn Gol river for a stretch before running through Buir Lake, and then turning sharply to the north-east up to the eastern Russian tripoint.