The Koshi or Kosi River (Nepali: कोशी नदी, koshī nadī कोसी नदी, kosī nadī) drains the northern slopes of the Himalayas in the Tibet and the southern slopes in Nepal. From a major confluence of tributaries north of the Chatra Gorge onwards, the Koshi River is also known as Saptakoshi (Nepali: सप्तकोशी, saptakoshī) for its seven upper tributaries. These include the Tamur Koshi originating from the Kanchenjunga area in the east, Arun River and Sun Koshi from Tibet. The Sun Koshi's tributaries from east to west are Dudh Koshi, Bhote Koshi, Tamba Koshi and Indravati Koshi. The Saptakoshi crosses into northern Bihar where it branches into distributaries before joining the Ganges near Kursela in Katihar district.