The national park, with an area of 537,424 rai ~ 860 square kilometres (330 sq mi)[2] is located in two mountain chains of the Phi Pan Nam Range, Mae Yom and Nampi, with a not-protected area in between. There are both mixed evergreen forests, dipterocarp forest and dry deciduous forests in the park area.
Doi Phu Nang, the mountain that gives its name to the park, with an altitude of 1,202 m, is the highest peak in the area. The sources of two tributaries of the Yom River are in this mountain.[3] The park also has scenic rock formations and two impressive waterfalls, Namtok Than Sawan and Namtok Huai Ton Phueng.[4]