Dafla, Abor, Miri and Mishmi Hills: Ranges of Arunachal Pradesh

Dafla, Abor, Miri, and Mishmi Hills form the outermost ranges of the Eastern Himalayas in Arunachal Pradesh, extending from the Kameng district in the west to the Dibang Valley in the east. These hills lie along the India–Tibet border, separating the Assam plains from the high Himalayas. Moreover, each hill range is named after the tribal communities inhabiting it.

1. Dafla Hills

• Location: Western Arunachal Pradesh, between the Kameng and Subansiri Rivers, along the border of Bhutan and Arunachal Pradesh.
• Tribe: Inhabited mainly by the Nyishi (Dafla) tribe.
• Elevation: Generally ranges from 1,000 to 2,000 metres.
• Rivers: Source region for the Kameng River and several tributaries of the Subansiri.
• Importance: Forms the westernmost section of the Outer Eastern Himalayas and acts as a natural barrier protecting the Assam plains.

2. Miri Hills

• Location: Between the Subansiri and Siang Rivers in central Arunachal Pradesh.
• Tribe: Occupied by the Miri (now called Mishing) tribe.
• Elevation: Around 1,000–1,500 metres.
• Rivers: The Subansiri River flows along its western margin.

3. Abor Hills

• Location: Between the Siang (Dihang) and Dibang valleys in central-eastern Arunachal Pradesh.
• Tribe: Inhabited by the Adi (Abor) tribe.
• Elevation: About 1,200–2,000 metres.
• Rivers: Siang River cuts deep gorges through these hills before entering Assam.
• Acts as a drainage divide between Siang and Dibang systems.

4. Mishmi Hills

• Location: Easternmost part of Arunachal Pradesh, near the China and Myanmar borders.
• Tribe: Inhabited by the Mishmi tribe.
• Elevation: Varies from 1,500 to over 3,000 metres.
• Rivers: The Dibang and Lohit Rivers originate here before joining the Brahmaputra.
• One of the biodiversity hotspots of the Eastern Himalayas.