Later they spread to Darjeeling Terai, Baikanthpur in Jalpaiguri district again marched further East and settled in the Dooars.

It is said that, a group of Mech people, again moved further East, crossed the Sankosh river, and went towards Goalpara in Assam.

Due to repeated floods in Dooars and eastern bank of Teesta river, many families migrated towards Assam.

[12][13] In Persian history, these three groups of people, the Koch, Mech and Tharu, possessed the physiognomy of the Turks and the Mongols and their speech was different from the rest of the subcontinent.

[17] 19th and 20th century's scholars state that designation Mech is name applied to western section of Bodos by others and also to some extent by the people themselves.