The reserve covers 205,000 hectares at 30 meters above sea level. By air from Banjarmasin, South Kalimantan, to Pangkalan Bun, Central Kalimantan, (PHPA Office) and then by road to Kumai (15 kilometers), then by boat on the Kumai and Sekunir Rivers into the reserve. This is an interesting boat trip through swamp forests full of bird life, particularly waterfowl; the Bornean proboscis monkeys, so-called from the large pendulous nose of the male, easily visible in the riverine trees. In the northern part of the reserve is a "rehabilitation station" for Bornean orang utans which is also the study area of resident scientists. There is a guest house at their camp. Advanced reservations are necessary. Take canned food along.
The reserve covers 200,000 hectares and goes up to 340 meters in altitude. By road from Samarinda, East Kalimantan, to Sangata, 80 kilometers to the north, by boat up to the Sangata river. In spite of timber exploitation and the logging access road, the reserve still contains large areas of good lowland rain forests. Boat trips with side excursions by foot offer a chance to see some of the hardwood forests of East Kalimantan.