Tarn Ngam Waterfall Forest Park is located in Pa Khun Huai Sam Pat-Khun Huai Kong See Forest reserve. It is a forest park of 78,125 rais in Nong Saeng District, Nong Saeng Sub Ampur, Udon Thani Province and was gazetted on19 December 1984 by Royal forest Department.

Topography
Topography in the area is steep mountain and a part of Bhu Parn ranges which is separated into long stripe in the North. The area is highly slope and form a plateau on the top. Many rivers flow into Sam Pat, Huai Num Kong and Huai Kong See river. Huai Wang Kum in particular is a dense forest. In the south there is a rocky ground called ‘Lae Sa-ard’

Climate
Climate in Num Tok Tarn Ngam Forest Park is devided into 3 distinct seasons. Rainy season starts from June-November. Winter begins from December-February. Summer is around March-May.

Flora and Fauna
The main vegetation types are evergreen forest and dry dipterocarp forest. Plant species found in the area are Pterocarpus macrocarpus, Afzelia xylocarpa, Peltophorum dasyrachis, Sindora siamensis, Dipterocarpus Spp., Shorea obtusa and Shorea siamensis for instance. Undergrowth species are Bamboo spp., Dendrobium Spp., Ferns and Phyllanthus Spp. Wildlife spotted here include Wild Pig, Barking Deer, Macaque, Mouse Deer, Gibbon, Flying Lemur, Civet and Birds.