In the ancient Indian tradition, two rivers are known to originate from Manasarovar Lake, in Mt. Kailas; one flowing to the east is called Brahmaputra and the other flowing to the west was called Shatadru, a tributary of the Sarasvati (joining the latter at Shatrana, Punjab) in Rigvedic times. Both these major rivers, Brahmaputra and Sarasvati are related to the God of creation, Brahma. The lower portion of the river is sacred to Hindus.

The Brahmaputra River flows 2,900 km from its source in the Kailas range of the Himalayas to its massive delta and the Bay of Bengal in Bangladesh. It flows through China, India, and Bangladesh, but its watershed includes Nepal, Bhutan, and Burma as well.The river drops steeply from high on the Tibetan Plateau through the world's deepest valley (5,075m) into northeast India where the river eventually merges with the Ganges and Meghna rivers to form the largest river delta in the world (60,000km2). The plains watered by the stream yield abundant crops of rice, jute, and mustard.

There are many mythological stories on Brahmaputra. But the most popular and sacred one is about the river's birth in 'Kalika Purana'. It describes how Parashurama, one of the ten incarnations of Lord Vishnu, got rid of his sin of murdering his own mother with an axe (or Parish) by taking bath in this sacred river. On strict order from his father Jamadagni (who had suspected his wife Renuka of adultery), Parashuram had to murder his own mother by severing her head with an axe.

As a result of this nefarious act, the axe got stuck to his hand and he was unable to take it off his hand. On advice from sages, he started on a pilgrimage and ultimately reached the place, which is presently known as Parashuram Kunda (about 25 km north of Tezu in Lomita district in Arunachal Pradesh). The story says that the mighty river was then confined to a Kind (or Kunda) or a small lake surrounded by hills. Parashuram cut down the hills on one side to release the sacred water for the benefit of the common people. By this act, Parashuram's axe came out of his hand to his great relief and he knew that he had been exonerated from his sin.

In another story, Shantanu, a famous ancient sage began a long meditation in an ashram in Kailash Manasaravor area along with his beautiful wife Amodha. Amodha was so beautiful that Lord Brahma himself became enchanted by the beauty of Amodha and requested her to make love with him. But Amodha did not accept the Brahma's proposal. However, by that time Lord Brahma had become so excited that his semen discharged at that place. When Shantanu came to know about this, he inseminated the Brahma's semen in the womb of Amodha. Subsequently, Amodha gave birth to a son and he was called Brahmaputra. The tank near the ashram of sage Shantanu is known as the Brahmkund. Another legend is that because Brahmaputra is the largest river in India, it carries a male name.