- Location: Spread across the Dibang Valley, Upper Siang, and West Siang districts of Arunachal Pradesh in the Eastern Himalayas, forming one of India’s largest and most ecologically diverse protected landscapes in the northeastern region.
- Geographical Setting: Lies between the Dihang River (known downstream as the Siang and later the Brahmaputra) to the south and the Dibang River to the north; forms a crucial part of the Eastern Himalayan biodiversity hotspot, recognized globally for its exceptional species richness and high levels of endemism.
- Biosphere Reserve Established: Officially declared as a Biosphere Reserve by the Government of India in 1998 to promote biodiversity conservation, scientific research, and sustainable development in this ecologically sensitive Himalayan region.
- National Park and Wildlife Sanctuary: Encompasses Mouling National Park and Dibang Wildlife Sanctuary, both of which serve as core conservation areas aimed at protecting rare wildlife species and fragile mountain ecosystems.
- Area: Covers a total area of approximately 5,112 km²; the zonation includes a Core area of about 4,095 km² and a Buffer zone of roughly 1,017 km², ensuring graded levels of protection and sustainable use.
- Hills: Dominated by the Mishmi Hills, a rugged mountain system characterized by steep slopes, deep valleys, high rainfall, and significant altitudinal variation that supports diverse habitats from lowland forests to alpine zones.
- Rivers: Named after the Dihang River (Siang/Brahmaputra) and the Dibang River—both major tributaries of the Brahmaputra system—which shape the valley landscapes, provide water resources, and influence local climate and biodiversity.
- Tribe: Indigenous groups including the Mishmi, Idu Mishmi, Adi, and Tangsa communities continue to inhabit surrounding areas, preserving rich oral traditions and ecological knowledge passed down through generations.
- Vegetation Types: Exhibits remarkable ecological diversity with subtropical broad-leaved forests, subtropical pine forests, temperate broad-leaved forests, temperate conifer forests, sub-alpine shrubs, alpine meadows, bamboo brakes, and high-altitude grasslands occurring across different elevation zones.
- Plants: Flora includes oak, laurel, magnolia, chestnut, rhododendron, fir, spruce, bamboo species, as well as alpine grasses and shrubs adapted to cold and high-altitude conditions.
- Animals: Supports significant wildlife such as the Tiger, Asian Elephant, Mishmi Takin (a rare mountain ungulate), Red Panda, Musk Deer, Asiatic Black Bear, clouded leopard, and numerous bird and reptile species typical of the Eastern Himalayan region.