[3] The ancient town of Kotawaringin is located in the valley formed by the river and its tributary along with gold and gemstone mining areas.

In the upper reaches of the tributary valley of Arut River the Pangkalan Bun town flourishes on its banks.

Lamandau River flows through southern Central Kalimantan and Pangkalan Bun, discharging into the Java Sea near Kumai at 2°51′20″S 111°43′14″E / 2.85556°S 111.72056°E / -2.85556; 111.72056.

Tributaries include the Arut River, where in its upper reaches the Pangkalan Bun town is located.

The capital of this district is Pangkalan Bun, which has a sub-district, a traditional area of the Dolang, close to the Kundangan city where 7000 Dayaks reside in about 100 longhouses spread over 19 villages.

Human exploitation in the area has led to the pollution of the Lamandau River from gold and zircon mining, illegal logging, and large-scale deforestation to create palm oil plantations.

The infrastructure facilities in these camps have been improved here since September 2003, with funding provided by the Orangutan Foundation, United Kingdom.