The Assam state government, in a gazette notification on August 1,2016 announced the addition of 350 sq km area in Chirang district of BTAD to Manas National Park, a World Heritage Site which forms a contiguous landscape with the Royal Manas National Park in Bhutan.

The additional area included in the ‘first addition’ is the eastern part of the Manas Reserved Forest, which is adjacent to the national park. The northern boundary of the first addition lies along the international boundary with Bhutan. With the addition of 350 sq km, the national park’s total area has now increased to 850 sq km.

The extension proposal was first moved by the Bodoland Territorial Council in 2013. In 2014, the state board for wildlife accepted the proposal, which was later cleared by the National Board for Wildlife and the Union ministry of environment, forests and climate change.

The area is home to the critically endangered white-bellied heron ( Ardea insignis)

The addition falls within the notified buffer of the Manas tiger reserve as well as the critical tiger habitat notified by the state government in 2007.