According to a 1980 source, between 2,200 and 3,500 Tsum (or Siyar) people live along the southern slopes of the Himalayan Range in central Nepal. In the 25 years since this estimate was made, it is thought that the population of the Tsum may have grown to exceed 5,000. The Tsum inhabit a number of villages in the northern Gorkha District of the Gandaki Zone, a short distance away from the China-Nepal border. The main Tsum village is called Chongong (also known as Chekampar).

Chongong is one of the overnight stops for trekkers doing the Langtang Trek. One guide book states, 'The trail descends through forest to the Langtang Khola at 1,890 metres [6,200 feet] then follows the river upstream, crossing from the southern to northern bank to reach Chongong at 2,380 metres [7,800 feet]...the villages around are in Tibetan style with stone walls around the fields and herds of yaks.' Unlike the barren Tibetan Plateau to the north, the Tsum area receives the monsoon rains. 'As a consequence the landscape is lush and green, and the fields support good harvests of corn in addition to the staple grains.'

The Tsum are also known as the Chumba, or Shar, because they live along the banks of the Shar (Eastern) River. Official books issued by the Nepali government tend to call them by these alternate names.

The closest neighbours to the Tsum are the Nubri people, who live along the upper reaches of the Buri Gandaki River just to the west. The Tsum area is just north of Ganesh Himal, which stands at 7,406 metres (24,292 ft.) above sea level.

The Tsum speak a Central Tibetan language, but linguistic studies have shown that it only shares 71 per cent to 78 per cent lexical similarity with Nubri, 60 per cent to 66 per cent with Lhasa Tibetan and 66 per cent with Kyerung. Few Tsum can speak more than a few words and phrases of Nepali. Their isolated mountain hideout has separated them from the main body of Nepali culture and language, and in most ways they are more aligned with Tibet than with Nepal. Many Tsum are traders, carrying grain and modern appliances from Nepal to Tibet, where they trade their goods for salt and wool.

Tibetan Buddhism dominates the lives of the Tsum people. Every family follows Buddha. They depend on lamas to keep peace between their communities and the spirits, and they spare no effort to placate the demons that can bring disaster to the Tsum's communities if they are offended. One visitor commented, 'The people of Nubri and Tsum are Buddhists...actively so, quite possibly because of their close proximity to and greater commerce across the northern frontier with Tibet. '

Very few Tsum people have ever been exposed to the gospel of Jesus Christ. Most are too busy with their daily lives to care enough to seek the truth. Most are content to follow Buddha, as countless generations of their ancestors have done before them.

Scripture Prayers for the Siyar in Nepal.