Kutai National Park has seen its share of troubles. All but abandoned in the late '90s as a conservation failure ransacked by logging and fires, new studies are showing all is not lost. The wild orang-utan population has recovered to as many as 2000 individuals, and pockets of forest are still relatively intact. The Prevab station near Sangatta offers one of Kalimantan's best chances to see truly wild orang-utans, and numerous guides and tour companies from Samarinda and Balikpapan know the park well.
From the ranger station, several kilometres of trails fan out through decent secondary forest, where large buttressed trees still provide plenty of hiding spots for orang-utans. The rangers are experts at moving slowly and listening for the telltale rustle of the canopy that betrays a critter's location. Bring mosquito repellent.