Upper Mahakam Interior: Towns, Lakes and Villages Compared

The upper Mahakam interior is the inland part of East Kalimantan that the Mahakam River drains from the highlands in the north-west, down toward the lower river and the coast. Two regencies share it. Mahakam Ulu Regency holds the upper valley itself, and West Kutai Regency lies to its south, holding the middle river, the lakes and the regency seat at Sendawar. Most people who think of the upper river are really thinking of a chain of towns, villages and lakes strung along one waterway, where the trip is set as much by water levels as by distance. Within the wider province of East Kalimantan, the land divides between these two regencies, the river sets the pace of travel, and the main places differ in ways that matter when you choose where to stay.

What the upper Mahakam interior covers

The interior is not one town with a river running past it. It is a set of riverside seats, district centres and smaller villages, several days apart by boat at the upper end, with road links that are limited and uneven. A visitor usually meets it in one of three ways: as a river journey that starts in Samarinda and works upstream, as an overland stay based in the West Kutai seat, or as a lake and village visit that leaves the river for a few days. Each approach suits different travellers, and the places below show where each one sits so you can match one to the other.

Before you plan a route, it helps to know that the names on the map do not all mean the same kind of place. Some are regencies, which are the largest administrative units. Some are districts, called kecamatan, which group several villages. Some are villages, called kampung or desa, where most people live. A regency seat may be a village inside a district, and a district name may be the same as a town name. Keeping those levels apart prevents most of the confusion people bring to the interior.

Two regencies share the upper river

Mahakam Ulu Regency: the upper valley

Mahakam Ulu Regency was carved out of the northern districts of West Kutai. Its creation was approved by the national parliament in December 2012 and formalised by a law in 2013, which makes it one of the newer administrative units in the province. It covers the upper valley of the Mahakam, and the river flows out of Long Apari district, one of its five districts. The regency has 50 villages in total and its capital is Ujoh Bilang, a village that lies inside Long Bagun district.

Two features of the regency shape almost every trip. The first is its northern border, which runs with Sarawak, the Malaysian state on Borneo. That frontier makes the regency’s northern edge an international one, and it adds to the sense that the regency sits far from the provincial centre. The second is access. Public services and transport links in the regency remain minimal, and the river is still the lifeline that connects the provincial capital with the inland villages. Anyone travelling upriver should assume that the boat is the main way in, and that the road network will not carry them the whole way.

The upper districts are not all alike. A village such as Long Tuyoq, a village settlement inside the regency, shows how the upper villages differ from the district centres. For most visitors, the practical centre of Mahakam Ulu is Ujoh Bilang and the Long Bagun district around it.

West Kutai Regency: the middle river and the regency seat

West Kutai Regency is the larger regency that surrounds Mahakam Ulu on the south. It has sixteen districts, and it is the regency from which the northern districts were split. Its seat is Sendawar, but Sendawar is not a single compact town. It is an area that spans parts of three districts: Barong Tongkok, Melak and Sekolaq Darat. That matters when you arrange a pickup, choose a hotel or work out whether a river visit fits into the same day as an errand. The distances inside Sendawar are not the distances on a map of a city, so plan by district rather than by street.

Sendawar is the place to understand as the administrative and economic centre of the regency. Barong Tongkok, the district that anchors it, has more villages under it than any other district in West Kutai and is the district closest to the regency’s own offices. Melak, further along the river, has its own town centre and works more as a river town than as a regency seat. Each of these is a different kind of base, and the difference is one of the first things to settle before you choose.

West Kutai also holds several river districts that are reached mainly by water. Long Iram is a district whose seat is Long Iram Kota, and it is the place that matters most when the river is low. It marks the point where a river trip becomes more demanding when the water is low.

How the river sets the pace of travel

The Mahakam is the spine of the whole interior, and its level changes the trip more than any other single factor. In the middle basin the lakes rise and fall with the river. Lake levels move from about half a metre to one metre in the dry season up to around seven metres in the rainy season, and the river follows the same cycle. A route that works in a wet month can be a slow or impossible one in a dry month, so the date of travel matters as much as the destination.

The river route from Samarinda, the provincial capital and the usual starting point, is the way most people enter the upper river. Samarinda is split by the river, which makes it the sensible place to ask about current conditions. For the full route, read the river route from Samarinda to Long Bagun. The point to take from it here is simple: the upper end of the route depends on water. When the level drops, the wooden boats that run from Samarinda reach no further than Long Iram, and the villages beyond it are out of reach until the water rises again.

The same logic applies inside the regency. Long Bagun, the district around Ujoh Bilang, has eleven villages. Its seat, Ujoh Bilang, is the regency capital and had 5,474 residents in the 2024 estimate. Travel between the district seat and the outlying villages is also river-based, so a plan that looks short on a map can take much longer in practice when the current is strong or the water is shallow.

In most cases the practical advice is to treat the river as the timetable. The higher the water, the further you can go; in low water, accept an earlier stop and enjoy the place you reach. Build a day or two of slack into any plan that depends on arriving at a particular upriver village, and do not promise yourself a fixed schedule for the last leg.

Lakes of the middle basin and why they matter

The middle Mahakam is a lake district as much as a river district. The basin holds roughly 76 lakes, and about 30 of them sit in the middle reach. The three largest are Jempang, Semayang and Melintang. Jempang is the biggest at about 15,000 hectares, Semayang covers about 13,000 hectares and Melintang is smaller than both, though still substantial. Together they form a linked chain rather than three separate basins, which means that conditions in one lake are connected to the others.

Lake Jempang is the lake most visitors to the interior meet first, and it lies within West Kutai. Its shoreline is not fixed. Because the level changes with the season, the shoreline and the water you see on one visit can look very different on the next, which is why the season should be part of the plan rather than an afterthought.

Fishing is the main livelihood around these lakes, and the river communities depend on it for food and income. Visitors should keep that in view. A lake is a working landscape, not a scenic backdrop, and the boats, nets and fish traps you see belong to people who rely on the water for their living. Stay respectful of working areas, ask before going into a fishing spot, and avoid treating a village shoreline as a viewing platform.

Choosing between the towns: a practical comparison

When you choose a base, the useful question is not which place is the most impressive but which one fits the way you want to move. The table below sets out the main places side by side, using the role each one plays in the interior.

Two rules make the table easier to use. First, a regency seat and a district centre are not the same thing, so check which one an address means. Second, the further up the river you go, the more you depend on the water and the fewer alternatives you will have if something changes. A base close to the middle river gives more room to adjust than a base at the end of a long boat journey.

For a first visit, most people do well with one base in West Kutai and one excursion into the lake country, rather than trying to reach the far end of Mahakam Ulu in a single trip. The regencies are large, the roads do not connect every village, and the interior rewards a slower pace. A second visit can add the upper valley once the first trip has shown how the river behaves in the season you travelled.

Villages, weaving and the Benuaq heartland

Tanjung Isuy is a Benuaq village and the administrative centre of Jempang district in West Kutai. It sits on the lake country that gives the district its name, and it is one of the places where the Benuaq way of life is most visible to a visitor. Daily life here is shaped by the lake: travel, fishing and the seasonal water are part of ordinary routines rather than something laid on for guests.

The best-known craft of the Benuaq is Ulap Doyo cloth, a woven textile made from the leaf fibre of the doyo plant. Benuaq women do the weaving, and the cloth is made into clothing, bags and other goods. The fibre has to be prepared before it can be spun and woven, so the cloth is slow work rather than a quick purchase. If you want to see the craft, ask whether a weaver is available that day rather than assuming one will be at work.

Respect the village’s customs when you visit. Longhouses and community spaces are used for their own purposes, and they are not museums. A visit that starts with a clear question about the weaving, asked politely and with a local guide, tends to go far better than one that treats the village as a stop on a route.

River wildlife and the pesut dolphin

The river is home to the pesut, the Irrawaddy dolphin, which is known in the Mahakam as the pesut Mahakam. It is a river dolphin listed under CITES Appendix I and recognised as threatened, and its survival depends on the condition of the river and its lakes. Sightings are not guaranteed on any given trip, so do not plan a journey around seeing one. If you do see a dolphin, keep your distance, keep the engine quiet and let the animal set the pace.

The same condition-of-the-river point applies to fishing, to the lakes and to the forest that surrounds them. Logging and mining are among the pressures on the river, and both affect the water that the dolphins and the villages depend on. Visitors can help by choosing guides and operators who keep boats clean, take their rubbish back to town and stay on established routes rather than cutting through grassland and shallow water.

Practical planning notes for the interior

Start with the trip, then choose the base. A river journey, a West Kutai base and a lake visit are three different plans, and each needs its own level of preparation. Decide which of them you are making before you look at accommodation, because the right base follows from the trip rather than the other way round.

Carry supplies you cannot assume will be available. Upriver shops are fewer and smaller, and the choice of food, fuel, medicine and phone signal narrows as you move away from the regency seats. Bring cash, because card payment is not something to rely on in the villages. Keep a small, dry bag for papers and electronics, since boat travel and rain are constant companions in this landscape.

Confirm the water level before you leave Samarinda and again at each stop. Ask people who run the boats or who live along the route, because they know the state of the channel better than any map. If the level is low, change the plan early rather than pushing on. Turning back at a sensible point is a normal part of river travel, not a failure of the trip.

Plan for the weather. The interior has a wet and a dry season, and each brings its own problems. In the dry months the river is shallow and the lakes pull back; in the wet months the water is high, the current is strong and some tracks become unusable. Neither season is wrong for a visit, but each suits a different kind of traveller, and a trip made in the wrong month can feel very different from the one you planned.

Questions people ask about the upper Mahakam interior

Is the upper Mahakam interior easy to reach?

It is reachable, but the river decides how easy. From Samarinda the journey upriver is possible in most seasons, yet the far end depends on water levels, and the regency’s road links are limited. Plan for the boat as the main route and treat any road as a useful extra rather than the way in.

Which regency should I base myself in?

For a first visit, West Kutai is the easier base. Sendawar, Barong Tongkok and Melak offer a larger base than the upper valley, and Long Iram is a practical stop on the way. Mahakam Ulu suits a longer stay, because its river connections take more time to plan.

Can one trip cover both regencies?

It can, but a single trip should be planned around the slowest leg. Crossing from the West Kutai lakes into the upper valley takes more time than the map suggests, and the water level can change the sequence. A trip that covers both regencies works best when it has spare days built in.