This seldom-explored park sprawls across a serrated mountain range along the Myanmar border. Billing itself as the 'land of fog and freezing rainforest', mornings at the park have a brooding beauty, particularly when cold-season mist fills the valleys. Most of the park is inaccessible, but visitors can enjoy waterfalls, trekking and the 'Tarzan' treetop accommodation near the end of one of Thailand's most remote and winding roads.
The park teems with wildlife, including elephants, tigers, bears, serow (Asian mountain goats), marbled cats and palm civets, though most animals are shy. That said, barking deer and kalij pheasant often wander through the visitor centre (8am to 4.30pm) and lodging area.
Thais know the park for its challenging ranger-led overnight treks (16km round trip) to 1249m Khao Chang Pheuk, which offers 360-degree views. The season is up to the weather, but trekking can begin as early as late November and lasts through January. The trek starts at E-Thong village, but registration is done at or before 7am at the visitor centre, 8km away. The cost is 2500B for up to 10 people (the park puts groups together) and porters are available for an extra fee. Numbers are limited so reservations are wise. Be prepared for leeches.
For a less-challenging bit of walking through healthy rainforest, let a ranger lead you (for a small tip) on a 4km two-hour walk from the visitor centre to Doi Tong Pala. Five kilometres southwest of the visitor centre, down a steep side road, Jokkadin Waterfall plummets 34m with force.
The serpentine 62km drive west from Thong Pha Phum town is along a paved but often potholed road. Yellow sŏrng·tăa·ou (passenger pickup trucks) to E-Thong pass the visitor centre (70B; 2¼ hours).