Drangme Chhu river drains a large portion of central and eastern Bhutan

Bhutan

Bhutan , officially the Kingdom of Bhutan, is a landlocked state in South Asia, located at the eastern end of the Himalayas and bordered to the south, east and west by the Republic of India and to the north by the People's Republic of China...

. The word Chhu means "river" or "water" in Dzongkha. The river rises in the western portion of Arunachal Pradesh

Arunachal Pradesh

Arunachal Pradesh is a state of India, located in the far northeast. It borders the states of Assam and Nagaland to the south, and shares international borders with Burma in the east, Bhutan in the west, and the People's Republic of China in the north. The majority of the territory is claimed by...

, India

India

India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

, and flows southwest first into the Bhutanese district (or dzongkhag

Dzongkhag

A dzongkhag is an administrative and judicial district of Bhutan. The twenty dzongkhags of Bhutan are further divided into 205 gewogs. Some larger dzongkhags have one or more of an intermediate judicial division, known as dungkhags , which themselves comprise two or more gewogs...

) of Trashiyangtse and then into Tashigang. The south flowing Kulong and the west flowing Gamri join the Drangme near the town of Tashigang. Continuing to the southwest, the river forms the boundary between Tashigang and Mongar

Mongar

Mongar is a town and seat of Mongar District in Bhutan. As of 2005 it has a population of 3502....

, and then between Pemagatsel

Pemagatsel

-External links:*...

 and Mongar. Along this stretch is the confluence with another major tributary, the south flowing Kuru

Kuru River

The Kuru River is a stream in the South Sudanese state of Northern Bahr el Ghazal. The town of Nymlal lies to its south.-External links:**...

, and a name change to the Manas River

Manas River

The Manas River is a transboundary river in the Himalayan foothills between southern Bhutan and India.It is named after Manasa, the serpent god in Hindu mythology.It is the largest river system of Bhutan, among its four major river systems; the other three are Amo Chu or Torsa, Wong Chu or Raidak,...

. Shortly before turning south and leaving Bhutan, the river is augmented again with the waters of the south flowing Mangde Chhu River. The lowest point in Bhutan is at the point where the Manas Chhu river crosses into India (Assam) near the town of Manas. The river empties into the Brahmaputra River

Brahmaputra River

The Brahmaputra , also called Tsangpo-Brahmaputra, is a trans-boundary river and one of the major rivers of Asia. It is the only Indian river that is attributed the masculine gender and thus referred to as a in Indo-Aryan languages and languages with Indo-Aryan influence...

some 50 miles (80.5 km) south of the Bhutanese border.