On the flood plains of the Sapta Koshi in Saptari and Sunsari district of eastern Nepal lies this reserve. It covers 175sq. km and it was established in 1976. Last surviving population (about 100) of wild buffalos is found there besides hog deer, spotted deer and blue bull. This reserve also assists the local economy by providing fishing permits and collection of edible fruits and ferns in seasons. Two hundred and eighty species of birds have been recorded there and the endangered Gharial, crocodile and Gangetic dolphin have been recorded in Koshi River. Numerous of water-holes and marshes make this one of the finest breeding areas in Nepal. The grasslands support an important population of the Asiatic wild buffalo.