This ecoregion covers an area of 83,100 km2 (32,100 sq mi) and constitutes a band of temperate broadleaf forests lying on steep mountain slopes of the Himalayas between approximately 2,000 and 3,000 m (6,600 and 9,800 ft).
It extends from the Kali Gandaki River in Nepal across Sikkim and West Bengal in India, Bhutan, the Indian state of Arunachal Pradesh and neighboring Myanmar.
), chiefly Quercus lamellosa, together with Lithocarpus pachyphylla, Rhododendron arboreum, Rhododendron falconeri, Rhododendron thomsonii, Magnolia doltsopa, Magnolia cathcartii, Exbucklandia populnea, Symplocos cochinchinensis, Cinnamomum cassia, Durio zibethinus, Artocarpus heterophyllus, Ficus benghalensis, Gnetum gnemon, Mangifera indica, Toona ciliata, Toona sinensis, Cocos nucifera, Tetrameles nudiflora, Shorea robusta, Camphora officinarum, Tsuga dumosa, Ulmus lanceifolia, Tectona grandis, Terminalia elliptica, Terminalia bellirica, Magnolia spp., Cinnamomum spp., and Machilus spp.
In the deciduous forests meanwhile the predominant tree species are Himalayan maple Acer campbellii, Juglans regia, Alnus nepalensis, Betula alnoides, Betula utilis, Larix griffithii, Picea brachytyla, Echinocarpus dasycarpus, Larix gmelinii, Larix sibirica, Larix × czekanowskii, Betula dahurica, Betula pendula, Pinus koraiensis, Pinus sibirica, Pinus sylvestris, Picea obovata, Abies sibirica, Quercus mongolica, Prunus padus, Tilia amurensis, Salix babylonica, Acer palmatum, Populus tremula, Ulmus davidiana, Ulmus pumila, Pinus pumila, Haloxylon ammodendron, Elaeagnus angustifolia, Tamarix ramosissima, and Prunus sibirica.
Other endemic mammals are Hodgson's giant flying squirrel (Petaurista magnificus), Namdapha flying squirrel (Biswamoyopterus biswasi) and Brahma white-bellied rat (Niviventer brahma), while endangered species found here include a population of Bengal tigers adapted to higher mountain slopes and having a high conservation priority.
Other endangered species include takin (Budorcas taxicolor) and Himalayan serow (a subspecies of Capricornis sumatraensis) as well as the vulnerable Mandelli's mouse-eared bat (Myotis sicarius), Assam macaque (Macaca assamensis), stump-tailed macaque (Macaca arctoides), dhole (Cuon alpinus), back-striped weasel (Mustela strigidorsa), clouded leopard (Neofelis nebulosa), and Irrawaddy squirrel (Callosciurus pygerythrus).