Yes , The Eastern Himalayas have been identified as a global biodiversity hotspot and counted among the 234 globally outstanding ecoregions of the world. 
 I do not know, but geographically there is alot to explore. Mountain rivers,fed by either melting snow ir monsoon rains empty into the Brahamputra River in India 
 Are there any specific reasons why they are rated so highly? 
 You are welcome 
 Could you tell me some facts about Bhutan's Geography?
Yes , The Eastern Himalayas have been identified as a global biodiversity hotspot and counted among the 234 globally outstanding ecoregions of the world.