Sumatran rhinos are the smallest of the living rhinoceroses and the only Asian rhino with two horns. Sumatran rhinos compete with the Javan rhino for the unenviable title of most threatened rhino species. While surviving in possibly greater numbers than the Javan rhino, Sumatran rhinos are more threatened due to habitat loss and fragmentation.
The Sumatran rhino once roamed as far away as the foothills of the Eastern Himalayas in Bhutan and eastern India, through Myanmar, Thailand, possibly to Vietnam and China, and south through the Malay Peninsula. Today, the species only survives on the Indonesian islands of Sumatra and Borneo. Experts believe the third subspecies is probably extinct.
Here is an article on the Sumatran rhino.