[1] Op Khan National Park (preparation) was officially established in 1992.

[2] The park spans the districts of Samoeng, San Pa Tong, Hang Dong, and Mae Wang.

[2] Khun Tian (ขุนเตียน) is the highest point at 1,550 metres above sea level.

The mountains in the park form part of the Thanon Thong Chai Range.

Trees include Irvingia malayana, Anisoptera costata, Tectona grandis, Lagerstroemia calyculata, and Schleichera oleosa, while wildlife includes mainland serows, common muntjac, fishing cats, mouse deer, Asian palm civets, mongoose, porcupines, and others.