Terhathum Districtतेह्रथुम जिल्ला

Terhathum (often spelled Tehrathum, as in the census tables) is the smallest district in Koshi Province at just 679 km², a wedge of hills between roughly 300 m and 3,000 m run from the ridge-top headquarters of Myanglung. With 88,731 people at the 2021 census it is also the province's least populous district, and its six local levels — two municipalities and four rural municipalities — are the fewest in Koshi.

Its natural claim to fame is the Tinjure–Milke–Jaljale (TMJ) ridge, popularly called the rhododendron capital of Nepal: a 285 km² forest belt shared with Sankhuwasabha and Taplejung that holds 28 of the 32 rhododendron species recorded in Nepal (per an IUCN compilation), turning the high ridgelines red and pink each spring. One of the district's two municipalities is even named Laligurans, Nepali for rhododendron — the national flower.

The district sits in the old Limbu heartland — Limbus are 36.4% of the population, followed by Chhetri (19.4%) and Bahun (11.1%) — and its hills are part of the eastern belt known for orthodox tea and traditional dhaka weaving. Literacy is a healthy 81.9%, but the population is falling fast (−1.30% a year, from 101,577 in 2011), the third-steepest decline in the province after Khotang and Bhojpur.