With the last surviving wild buffalo found here, this reserve was uniquely built to accommodate the 100 Plus wild water buffalos.
With an area of 176 square kilometers, it is also the smallest reserve and houses about twenty other animal species. Located on the banks of Sapta Koshi river there are around 439 species of birds recorded as 80 species of fishes swim the waters. The endangered Gharial Crocodile and Gangetic Dolphins have also been sighted in the Koshi River.
The vegetation is mainly composed of grassland, scrub and deciduous forests as local villagers are permitted to collect thatch grass once a year.