is common at the Banke Tal. The visit of Sir D.B. Brandis in 1860 to the area culminated in a forest area of the present day Dudhwa National Park being brought under the control of Government in 1861 for preservation. In Kheri District all the Sal and miscellaneous forests and grasslands in Kharigarh Pargana, between the Mohana and Suheli rivers, were included in the then North Kheri Forest Division. More areas were reserved for protection between 1867 and 1879 and added to the Division. The area of the Division was legally constituted as Reserved Forests in 1937. The Sonaripur Sanctuary, comprising , was created in 1958 to specifically protect swamp deer (Cervus duvaceli duvaceli). The area was too small and was later enlarged to and renamed as Dudhwa Sanctuary in 1968. Later, more area was added to the Sanctuary and in 1977, it was declared Dudhwa National Park. The total area of the Park was of which was the core zone and the balance of was a buffer zone. The area was established in 1958 as a wildlife sanctuary. On 1 February 1977 wildlife sanctuary became a national park and after 11 years in 1988 it was established as a tiger reserve. Dudhwa Tiger Reserve lies on the India-Nepal border in the foothills of the Himalaya. Dudhwa Tiger Reserve was created in 1987–88 comprising Dudhwa National Park and Kishanpur Sanctuary (). With an addition of to the buffer zone in 1997, the present area of the tiger reserve is . Distance from Lakhimpur railway station to Dudhwa is about by road. Demographics According to the 2011 census Lakhimpur Kheri District has a population of 4,021,243 roughly equal to the nation of Liberia or the US state of Oregon. This gives it a ranking of 56th in India (out of a total of 640). The district has a population density of . Its population growth rate over the decade 2001–2011 was 25.38%. Kheri has a sex ratio of 894 females for every 1000 males, and a literacy rate of 60.56%. Scheduled Castes and Scheduled Tribes made up 26.40% and 1.33% of the population respectively. The tribal population are Tharus living along the Nepal border. At the time of the 2011 Census of India, 93.25% of the population in the district spoke Hindi (or a related language), 3.10% Urdu, 1.83% Punjabi and 1.36% Bhojpuri as their first language. Languages spoken here include