The Reserve covers 175 Sq.Kilo Meters. It was established in 1996. Numerous water-holes and marshes make this one of the finest birding areas in Nepal. The grasslands support an important population of the Asiatic buffalo. 

Koshi Tappu Wildlife Reserve first Gazettes back in1976 was mainly established to protect the rare wild water buffaloes. The area of the reserve extends 175 sq. km. to the north of one kilometer long barrage that spans the Koshi river. The vast expanse of water created by the barrage, marshes, lagoons, mudflats and arable land that lie around it offers an outstanding wetland which has about to created one of the best and finest bird watching sanctuaries in Asia.

One of the most rewarding and greatest assets of Koshi Tappu Wildlife Park is that it offers ample scope for nature walks. For those with curiosity and perseverance, walking within the reserve on foot is the most profitable way of exploring the grassland, river lagoons and woodlands and vicinity of the barrage, just a short drive away.

The best time too visit this fabulous wildlife reserve is between October to March when much of the migratory and local birds can be sighted by the barrage and many of the river channels. Numerous Himalayan peaks including the Makalu I (8,463 m), the fifth highest mountain in the world can be seen during the clear time of the year.