Inter-State and International Borders of Assam
Assam sits in the heart of the North-East and touches two countries and seven states, which makes its boundary a very important and very examinable topic. To the north and north-west the state meets Bhutan, and to the west and south-west it meets Bangladesh. Within India, Assam shares its border with seven states: Arunachal Pradesh, Nagaland, Manipur, Meghalaya, Tripura, Mizoram and West Bengal. This topic is full of district names, river boundaries and border towns, so it is best learnt by grouping the borders into the international ones and the inter-state ones.
The international borders
Assam has an international boundary only with two countries, Bhutan and Bangladesh, and its total international border is about 288 kilometres. The border with Bhutan is about 267 kilometres long and runs along the districts of Kokrajhar, Chirang, Baksa, Udalguri, Darrang, Sonitpur and Bishwanath. The border with Bangladesh is much shorter, about 21 to 22 kilometres, and lies mainly in the districts of Dhubri and Karimganj. In the Dhubri area the boundary with Bangladesh is formed by the Brahmaputra itself, which on entering Bangladesh is known as the Jamuna, while the Barak flows into Bangladesh and becomes the Surma and later the Meghna.
The inter-state borders
Assam's longest inter-state border is with Arunachal Pradesh. The districts along that border are Tinsukia, Dibrugarh, Lakhimpur, Dhemaji, Sonitpur, Biswanath and Baksa, and the Brahmaputra with its tributaries such as the Siang and the Dibang mark parts of this boundary. With Nagaland, the districts are Golaghat, Jorhat, Sivasagar and Charaideo. With Manipur, the districts are Cachar and Hailakandi. The border with Meghalaya is the longest of the southern borders and touches Kamrup, Goalpara, Karbi Anglong, Dima Hasao, Cachar, Karimganj and West Karbi Anglong, with the Simsang and the Kopili forming part of the boundary. The border with Tripura touches Hailakandi, and the border with Mizoram touches Cachar, Hailakandi and Karimganj. Assam also shares a short border with West Bengal along Kokrajhar, Dhubri and Chirang.
Border towns, customs and passes
On the Bhutan border, the important neighbouring town is Samdrup Jongkhar in Bhutan, which is reached through the Darrang and Sonitpur side. On the Bangladesh border, the main land customs station of Assam is at Karimganj, which is an important centre of trade. Many routes into Bhutan pass through the Bhutan hills and the Buxa area. The district of Karimganj is notable because it is hemmed in by Bangladesh, Tripura and Mizoram on different sides.
Rivers as borders
Rivers form natural boundaries over long stretches. Between Assam and Meghalaya, the Simsang and the Kopili mark parts of the boundary. Between Assam and Arunachal Pradesh, the Brahmaputra and its tributaries the Siang and the Dibang mark the boundary. On the Bangladesh side in Dhubri, the boundary follows the Brahmaputra (Jamuna), and the Barak river leaves the state to enter Bangladesh. These rivers make both communication and boundary management difficult, especially in the flood season.
Some boundary extremes
The easternmost part of Assam lies near Sadiya in Tinsukia district, and the westernmost part lies in the Dhubri area. The south-western border districts are Kokrajhar and Dhubri. Remembering these extremes helps in map-based questions and in matching questions about districts and directions.
How to prepare this topic
- Learn the two countries and the seven states first, then fit the districts into each border.
- Fix the lengths: about 288 kilometres of international border, about 267 kilometres with Bhutan and about 21 to 22 kilometres with Bangladesh.
- Recall the rivers that act as borders: the Brahmaputra and its tributaries in the north, the Simsang and the Kopili in the south, and the Jamuna in the west.
- Memorise the key towns and stations: Samdrup Jongkhar on the Bhutan side and Karimganj as the main land customs station.
- Use a map to mark the extremes and the special district of Karimganj, which touches Bangladesh, Tripura and Mizoram.
Common exam traps
- The longest inter-state border of Assam is with Arunachal Pradesh, not with Meghalaya, even though the Meghalaya border is long.
- The Bhutan border is far longer than the Bangladesh border, so do not mix up the two lengths.
- Karimganj, not Dhubri, is the main land customs station on the Bangladesh side.
- The Brahmaputra becomes the Jamuna in Bangladesh, and the Barak becomes the Surma and then the Meghna.
Frequently Asked Questions
With which countries and how many states does Assam share its borders?
Assam shares international borders with two countries, Bhutan and Bangladesh, and its total international border is about 288 kilometres. Within India it shares borders with seven states: Arunachal Pradesh, Nagaland, Manipur, Meghalaya, Tripura, Mizoram and West Bengal. The border with Bhutan is about 267 kilometres long and the border with Bangladesh is only about 21 to 22 kilometres long.
Which is the longest inter-state border of Assam and which districts lie along it?
The longest inter-state border of Assam is with Arunachal Pradesh. The districts along this border are Tinsukia, Dibrugarh, Lakhimpur, Dhemaji, Sonitpur, Biswanath and Baksa, and the Brahmaputra with its tributaries such as the Siang and the Dibang marks parts of this boundary. The border with Meghalaya is also long but shorter than the border with Arunachal Pradesh.
Which rivers form the boundaries of Assam?
Between Assam and Meghalaya the Simsang and the Kopili mark parts of the boundary, and between Assam and Arunachal Pradesh the Brahmaputra and its tributaries the Siang and the Dibang mark the boundary. On the western side in Dhubri the boundary with Bangladesh follows the Brahmaputra, which in Bangladesh is called the Jamuna, and the Barak flows out of Assam into Bangladesh where it becomes the Surma and later the Meghna.
What are the main land customs station and border town of Assam?
On the Bangladesh border the main land customs station of Assam is at Karimganj, which is an important centre of trade. On the Bhutan border the important neighbouring town is Samdrup Jongkhar in Bhutan, reached through the Darrang and Sonitpur side, and many routes into Bhutan pass through the Bhutan hills and the Buxa area. Karimganj district is notable as it is surrounded by Bangladesh, Tripura and Mizoram on different sides.
Which are the easternmost and westernmost parts of Assam?
The easternmost part of Assam lies near Sadiya in Tinsukia district, and the westernmost part lies in the Dhubri area. The south-western border districts are Kokrajhar and Dhubri. Keeping these extremes in mind helps in map-based questions and in matching districts with directions, and it is useful to remember that Dhubri also lies along the Bangladesh border formed by the Brahmaputra.