From 1968 to 1981 the park's forest was used as a base for guerrillas of the Communist Party of Thailand. On 1 May 1995 an area of in the Khao Polok Lon National Forest, originally named Namtok Than Thip Forest Park, was declared as Khao Kho National Park. A survey was set up of Khok Sam Sang forest, Khao Polok Lon forest, Khao Pang Kho forest and Wang Chompu forest in the area of Lom Kao district, Lom Sak district, Khao Kho district and Mueang Phetchabun district of Phetchabun province on 16 August 2001. Later on 18 May 2012 Khao Kho National Park, with an area of has been declared the 125th national park and is managed by Protected Areas Regional Office 11 (Phitsanulok).