Which of the following rivers is a Trans-Himalayan river?

Sutlej is the right answer. It rises near Lake Rakas Tal in the Mansarovar region of Tibet, flows westward parallel to the Himalayas, then cuts through the range via a deep gorge near Shipki La before entering India in Himachal Pradesh. Rivers that originate north of the main Himalayan range and cross it are called Trans-Himalayan rivers. The group includes the Indus, Sutlej and Brahmaputra (Tsangpo).

• Jhelum: rises at Verinag in the Pir Panjal range of Kashmir, so it is a Himalayan river, not a trans-Himalayan one.
• Ganga: formed at Devprayag by the Bhagirathi and Alaknanda, both rising in Uttarakhand. It is a Himalayan river.
• Ravi: rises near Bara Bhangal in the Kangra region of Himachal Pradesh, in the Dhauladhar range. It is a Himalayan river.

Core concept: drainage systems and the classification of Himalayan rivers by origin. Mains angle: the Sutlej's Tibetan origin matters for the Indus Water Treaty, where the Sutlej is one of the eastern rivers allocated to India, and for trans-boundary water issues with China.

Trap: aspirants pick Jhelum or Ravi because they flow through Jammu and Kashmir or Punjab and look like major Himalayan rivers, forgetting that the test is origin north of the main range.