In 1940, Kaziranga was declared a sanctuary.
Lying along the mighty Brahmaputra River, the Kaziranga National Park covers an area of about 430 sq. km. Its swamps and grasslands with tall thickets of elephant grass and patches of evergreen forest, support the largest number of rhino in the subcontinent. It was an alarming depletion in their numbers, due to hunting and poaching that led to the conservation of this area in 1926.

At Kaziranga, the open country makes wildlife viewing fairly easy. A day's outing is often sufficient for visitors to see most of the major species here. Elephants take them into the Park at dawn. As the mist lifts and the rising sun touches the hills in the distance, herds of barasingha and wild buffalo are to be seen in the marshes.

The most ferocious bovine in the world, the massive wild buffalo is impressive and can weigh up to 915 kg. Rhinos browse unconcernedly as the visitors pass by and an occasional herd of elephants or wild boar is also sighted.
The grasslands are raptor country and the crested serpent eagle, the Pallas fishing eagle and grey headed fishing eagle can be seen circling over the marshes.

The water-bird variety includes swamp partridge, bar-headed goose, whistling teal, the Bengal florican, storks, herons and even pelicans.

Beside ofcourse the great one horned Indian Rhino, the other major wild attractions include a large population of Indian Elephants, Indian Bison, Swamp Deer or Barasingha, Hog Deer, Sloth Bears, Tigers, Leopard Cats, Jungle Cats, Otters, Hog Badgers, Capped Langurs, Hoolock Gibbons, Wild Boar, Jackal, Wild Buffalo, Pythons, Monitor Lizards, etc.

Kaziranga National Park is a birding paradise; the grasslands are a raptor country that can be seen on safari makes a remarkable experience. These include the Oriental Honey Buzzard, Black-Shouldered Kite, Black Kite, Brahminy Kite, Pallas's Fishing Eagle, White Tailed Eagle, Grey-Headed Fishing Eagle, Himalayan Griffon, etc. Huge numbers of migratory birds descend on the parks lakes and marshy areas during winters, including Greylag Geese, Bar-Headed Geese, Ruddy Shelduck, Gadwall, Falcated Duck, Red-Crested Pochard and Northern Shoveller.