The 1991 addition included the entire Kalagarh forest division, assimilating the 301.18 km2 (116.29 sq mi) area of Sonanadi Wildlife Sanctuary as a part of the Kalagarh division. It was chosen in 1974 as the location for launching Project Tiger, an ambitious and well known wildlife conservation project. The reserve is administered from its headquarters in the district of Nainital.