The revision of Protected Area System of Bhutan in 1993, merged Kulong Chhu Wildlife Sanctuary and the Boomdeling conservation area and gazetted in 1994 to be called as Boomdeling Wildlife Sanctuary to enhance biodiversity conservation through adoption of climate smart interventions for sustainable management of natural resources and improvement of livelihoods of local communities. The Sanctuary encompasses parts of Trashi Yangtse, Lhuntse and Mongar with the total area of 1534.24 Sq.Km. The Sanctuary has altitude ranging from 1390-6400 meter above sea level (masl) providing home for 966 species of plants, 52 species of mammals, 356 species of birds, 200 species of butterflies and 18 species of snakes (BWS, 2018). It is also home to charismatic, endangered and vulnerable species such as Snow Leopard (Panthera uncia), Tiger (Panthera tigris), Red Panda (Ailurus fulgens), Black-Necked Crane (Grus nigricollis), Ludlow’s Bhutan Glory (Bhutanitis ludlowi) and many more species.  

The Boomdeling valley, which includes roosting and feeding sites of Black-necked Crane was declared as RAMSAR site, a wetland of international importance in the year 2012. The beautiful (National Butterfly of Bhutan) Ludlow’s Bhutan Glory (Bhutanitis ludlowi) can only be found in Boomdeling, Trashi Yangtse. The Sanctuary is blessed with many important religious sites such as Pemaling, Rigsumgoenpa (Pelritse), Khachendra, and Dechenphodrang under Boomdeling Gewog. The people of the Boomdeling Gewog in Trashi Yangtse have developed incredible skill of woodworking (Dapa making) and traditional paper making (Desho). These are the main reasons for being the Sanctuary as one of the hotspot for ecotourism.