This Park is the largest and most undisturbed wilderness area in the Terai. It is thickly forested with sal trees, and is carpeted with grass, savannah and river line forest. It is regenerated habitat for endangered species like the rhinoceros, wild elephant, tiger, swamp deer, black buck, gharial, crocodile and Gangetic dolphin. Endangered birds include the Bengal florican, lesser florican, silver-eared mesia and sarus crane.