The Gandak River originates near the Nepal-Tibet border at an altitude of 7,620 m to the north-east of Dhaulagiri and flows about 100 km in a south-easterly direction in Nepal. It is known as Kali in Nepal. After that it debauches into the plains of the Champaran district of Bihar at Trivani. A number of tributaries, such as the Mayangadi, the Bari, the Trisuli, the Panchnad and the Sonhad join the river. The total length of the river from its source to outfall into the Ganga is 630 km of which 380 km lie in Nepal and Tibet. The total drainage area of the river is 46,300 sq. km of which 7,620 sq. km is in India.