Mahakam Ulu Regency

Mahakam Ulu Regency (Indonesian pronunciation:[maˈhakamˈulu], lit. 'Upper Mahakam') is a regency (kabupaten) in the province of East Kalimantan, Indonesia. As the name implies, it comprises the upper valley of the Mahakam River. It covers a land area of 15,314.8 km². The regency was established on 14 December 2012, formed from the former northern districts of West Kutai Regency.^[3] The districts now forming the regency held a combined population of 24,994 at the 2010 Census;^[4] the population for the new regency at the 2020 Census was 32,513;^[5] the official estimate as at mid 2025 was 39,962 (comprising 21,328 males and 18,634 females).^[1] The administrative capital is at Ujoh Bilang, which had 5,474 inhabitants as at mid 2024.^[6]

Mahakam Ulu shares borders with Kapuas Hulu (West Kalimantan) to the west; Murung Raya, North Barito (Central Kalimantan), and West Kutai to the south, Kutai Kartanegara to the east, and Malinau to the north. It is also the only regency in East Kalimantan to share an international land border with the Malaysian state of Sarawak (Kapit), to the north. Mahakam Ulu is also notorious for being geographically isolated from the rest of East Kalimantan. As a result, the public services and transportation access are still minimal.^[7]

The regency is divided into five districts (kecamatan), tabulated below with their areas and their populations at the 2010 Census^[4] and 2020 Census,^[5] together with the official estimates as at mid 2025.^[1]

Notable settlements include the twin villages of Tiong Ohang and Tiong Bu'u in Long Apari District.^[8] The table also includes the locations of the district administrative centres, the number of administrative villages (all classed as kampung or desa) in each district, and its post code.