West Kalimantan covers the west coast of Indonesian Borneo, sharing land borders with the Malaysian state of Sarawak to the north and East and Central Kalimantan to the east. The terrain of West Kalimantan ranges from a mountainous region of dense forest in the north and southeast to the low-lying swamps of the Kapuas River valley and more than 100 rivers that flow to the Java Sea and Karimata Strait. About 63 per cent of the 147,000 km2 province is a peatland.

In West Kalimantan, USAID SEGAR work in Kubu Raya, Sanggau, Sintang, and Ketapang Districts.