It’s a jungle out there. Exotic birds call, an orangutan swings in the branches and a rare fresh water dolphin leaps beside the passing boat. A cruise along the Mahakam, East Kalimantan’s, longest river, is a journey that takes the traveller into the living heart of Borneo.

The fabled Mahakam River (Sungai Mahakam) snakes sinuously for over 900 kilometers from the central mountains to Samarinda and the sea through some of the world’s richest remaining ecosystems. Its waters also carry a cargo of human history. Sultans, pirates, Dayaks and European adventurers plied the river in search of treasure, territory and human heads. Their exploits live on in literature and legend.

The Mahakam Adventure

These days a journey on the Mahakam is still an adventure. Rising in the highlands near the Sarawak border, the upper river tumbles over a series of dangerous rapids. The Dayak in this remote region live by subsistence agriculture and the occasional sale of birds’ nests, rattan and gold.

Few travellers brave the perilous white water of the upper river, and transport and supplies are expensive in this isolated area. The village of Long Bagun, 300 kms from the headwaters, is as far as most river traffic can travel, with the big boats ending their journeys at Long Iram.

The broad highway of the middle Mahakam is easily accessible, though tourists are still quite rare. Several tour companies offer river safaris in houseboats starting from Samarinda or Balikpapan, also the beginning of the challenging cross-Borneo trek.  Most tours feature a combination of river trips, visits to parks, wildlife observation, jungle treks and cultural encounters with traditional Dayaks.

Life on the Big River

Dayak tribes continue to dwell in their customary longhouses along the river and most welcome visitors. Many still practice the old religion of spirit worship – decorating their bodies with intricate tattoos, sporting heavy iron earrings and hunting the creatures of the jungle for meat.

The river’s waters, rainforests and floodplain are home to a wealth of flora and wildlife found nowhere else in the world. Almost 150 indigenous freshwater fish species found here include the critically endangered freshwater or Irrawaddy dolphin (Orcaella brevirostris). And about 300 species of birds, 70 of them protected, call from the forest. Treks and short detours from the main river reveal a treasure trove of unusual wild orchids, orangutans, sun bears, reptiles and proboscis monkeys.

The Mouth of the Mahakam

The river widens as it approaches the sea, fed by tributaries and punctuated by large and small lakes. The villages along its banks grow into towns and small cities as river traffic increases. Passing through the bustling capital of Samarinda, the river soon divides into a vast delta of mangroves and swamp before meeting the sea at the Makassar Strait, its epic journey over.

The Mahakam River In Photographs