This reserve was established in 1976. Its area is 1756 sq. km. This reserve lies in the flood plains of the Sapta-Koshi in the mid-east Nepal, and is a favorite spot for bird enthusiasts. The reserve's vegetation includes spreads of tall grass and patches of sisoo forest. The last surviving herd of wild buffaloes in Nepal is found here. Other species include wild boar, hog beer, spotted deer and blue bull called nilgai. A total of 280 species of birds, including ducks, ibises, egrets, herons and floricans, are recorded here. This area is extremely important for migratory birds. Other animal species include the crocodile, gharial and the Gangetic dolphins. Commercial fishing is also an important activity here.