South Salmara Mankachar district was created by bifurcating Old Dhubri district in 2016. On 15 August 2015 Assam's Chief Minister announced 5 new administrative district in Assam; South Salmara Mankachar was one among those. On 9 February 2016 Commissioner, Lower Assam and Central Assam Division, IAS inaugurated South Salmara Mankachar as an administrative district. Geographical coordinates of South Salmara Mankachar district is 25° 55' 0" North, 90° 1' 0" East.

    The district headquarter is located at Hatsingimari town which is situated at about 245 km from Guwahati. It shares its borders with Bangladesh in the west and Meghalaya in the south-east. The general topography of South Salmara Mankachar district is plain with patches of small hillocks like Bansali, Rangatari, etc. All these are situated in the southwestern part of the district. Mighty river Brahmaputra is flowing through this district from east to west with its tributaries. 
    How to reach:
    By Air: Nearest airport at Rupshi is about 72.8 km away from the headquarter Hatsingimari . It was constructed during World War II by the British Govt. mainly for military purpose. Since 1983 the airport is not in operation However, recently the ministry of DONER, GOI, has taken some initiative to renovate and functionalise the airport.
    By Water: The town had a very busy river port on the bank of the Brahmaputra, which was used as an international trade centre with the neighbouring countries, especially in the British era. At present, small ferries transport people to and fro Dhubri every day.
    By Road: Presently there is no National Highway in the district. Transportation takes place through state maintained pwd roads. There are two routes by road, one via Agia, Goalpara district and another via Tura, Meghalaya.