Nagarahole is named after Nagarahole (Cobra river in the local language, Kannada), a winding river which runs eastwards through its centre. Situated in the two districts of Mysore and Kodagu in the state of Karnataka.
It was originally constituted into a sanctuary in the year 1955 covering an area of 258 sq. kms and subsequently enlarged to include the adjoining areas of Mysore district and now extends over an area of 643.39 sq. kms which was given the status of a National Park in 1983.
Nagarahole National Park forms apart of the Nilgiri Biosphere Reserve and together with Bandipur National Park (875 sq. kms) and Mudumalai Wildlife Sanctuary (325 sq. kms) to its South East and Wayanad (350 sq. kms) to the South-West, is one of the last remaining and best protected habitats for endangered species like the Elephant and the Tiger.