Explanation:

Dibru-Saikhowa National Park is a national park located in Dibrugarh and Tinsukia districts, Assam, India. It was designated a Biosphere Reserve in July 1997 with an area of 765 km2 (295 sq mi), including a core area of 340 km2 (130 sq mi) and a buffer zone of 425 km2 (164 sq mi).

The area was declared as Dibru Reserved Forest in 1890. In 1920, additional area was added to the Dibru Reserve Forest. In 1929, Saikhowa Reserve Forest was declared. In 1933, more area was added to the Dibru RF. In 1986, an area of 650 km2 was preliminarily declared as a wildlife sanctuary out of which finally 340 km2 was declared as wildlife sanctuary in 1995. In 1997, Dibru-Saikhowa Biosphere Reserve was declared with and area of 765 km2 that included the 340 km2 of sanctuary area as the core. In 1999, the 340 km2 of sanctuary area was declared as national park.