Rapid and complete inundation of the reserve to depths ranging from 10 to 300 cm. occurs during the monsoon. The Sapta-Koshi river also changes its course from one season to another. The vegetation is mainly tall Khar-pater grassland with a few patches of Khair-sisso, scrub forest and deciduous mixed riverine forest.

The reserve offers important habitat for a variety of wildlife. The last surviving population (about 100 individuals) of Wild Buffalo or Arna are found here. Other mammals occurring here are hog deer, wild deer, spotted deer and blue bull. The reserve also assists the local economy by providing fishing permits and allowing the collection of edible fruits and ferns in season.

A total of 280 different species of birds have been recorded in the reserve. These include 20 species of ducks, 2 species of ibises, many stroks, egrets, herons and the endangered swamp partridges and Bengal floricans. The endangered Gharial, Crocodile and Gangetic dolphin have been recorded in Koshi river.

Entry Fee Per Person Per Day :
For Nepalese Nationals, Rs. 20/-
For SAARC Nationals, Rs. 200/-
For Other Foreign Nationals, Rs. 500/-

Access : Koshi Tappu is easily accessible from Kathmandu, being well connected by a national highway. There are daily flights from Kathmandu to Biratnagar and road connected Biratnagar to national highway.

Note : It is possible to combine with some other activities such as white water rafting and wildlife safari. The itinerary can be customized according to your duration of holiday.