It was named after the famous freedom fighter C.Rajgopalachari popularly known as "Rajaji". Rajaji National Park is spread over an area of 820.42 sq km. Subsequently in 2015, 255.63 sq km area of adjacent reserve forest was added to the area of Rajaji Naitonal Park as buffer zone and whole area of 1075 sq km was declared as Rajaji Tiger Reserve under the provision of Wild Life Protection Act 1972.