TheIndian Himalayan Region (abbreviated toIHR) is the section of theHimalayas within theRepublic of India, spanning thirteenIndian states and union territories, namelyLadakh,^[1]Jammu and Kashmir,^[2][3][4]Himachal Pradesh,Uttarakhand,Sikkim,West Bengal,Manipur,Meghalaya,Mizoram,Nagaland,Tripura,Assam, andArunachal Pradesh.^[5][6][7][8] The region is responsible for providing water to a large part of theIndian subcontinent and contains various flora and fauna.^[9]

Physiographically, the Himalayas start from the foothills of south (Sivaliks) and extend up to the Tibetan plateau of the north (Trans-Himalaya). Three major geographical entities, the Himadri (greater Himalaya), Himachal (lesser Himalaya) and theSivaliks (outer Himalaya), extend almost uninterrupted throughout its length and are separated by major geological fault lines. Huge but older waterways like theIndus,Sutlej, Kali,Kosi andBrahmaputra cut steep gorges through the main Himalayan range to escape into the Great Plains, establishing their antecedence.

The northernmost range of mountains are the trans-HimalayanKarakoram Mountains that continue from India into Pakistan and China. To the south of the Karakoram Range lie theZanskar andLadakh ranges.

Some of the highest mountains on Earth are also found in the region. Many perennial, glacier-fed rivers flow from the Himalayas.

Trans-Himalaya ranges in India include the Karakoram, Zanskar and Ladakh ranges that run through Ladakh and Himachal Pradesh. At the eastern end, some portion of theKangri Karpo (a trans-Himalayan range) forms part of the northern boundary of Arunachal Pradesh with Tibet.

The Karakoram is a giant range, which geographically divides India andCentral Asia. The range consists of high mountain peaks likeK2, Rimo and Teram Kargri. TheKorakoram Pass acts as the main connector between the markets ofYarkand, Leh andKashgar.

To the north of the Leh lies the Ladakh Range which is an important part of the Trans-Himalayan range that merges with theKailash Range in Tibet. Here, the important passes are the famousKhardung La, andDigar La, which lie to the northeast of Leh.

The Zanskar Range lies to the north of the main Himalaya. It acts as a backbone of Ladakh south of the Indus River, extending 250 kilometres (160 mi) from theKarcha (Suru) River nearKargil in the northwest toTso Kar in the southeast. The range separatesIndus Valley from theZanskar Valley. It is divided from the main Himalaya by theStod,Tsarap andZanskar valleys. Some of the main passes are theFatu La, on the Leh-Srinagar road, while the main trekking passes into the Zanskar valley are Singge La, the Cha Cha La and the Rubrang La.

To the south of the main Himalayas lies the lesser Himalayan Pir Panjal Range, with an average height of 5,000 metres (16,000 ft), in Jammu and Kashmir and Himachal Pradesh. The Kashmir valley is bounded by this range to its west and south. The resort town ofGulmarg is located on the northern slope of the range. Important passes include theBanihal pass, the Pir Panjal pass, theSinthan pass and theRohtang pass.

To the south of the Pir Panjal lies the Dhauladhar range. It lies to the north of theKangra valley, from where it appears to rise almost vertical. It forms the water divide between theRavi and Beas rivers. In the west it divides the Chenab valley and the Tawi Valley. It is located mostly in Himachal Pradesh.

The southern most range of the Himalayas are the Sivaliks. Sivaliks extend over a width of 10–50 km, and have an altitude varying between 900 m and 1100 m.

These ranges are called by different names in different regions:

• Jammu Hills in Jammu region
• Mishmi Hills in Arunachal Pradesh

These parts consist of thick gravel and alluvium.

The valley lying between the Lesser Himalayas and Shivalik ranges are called as Duns. Dehradun, Kalka Dun and Jammu Dun are some of the prominent Duns. It is the southern most region of the Himalayas.

• Himalayan Rim
• Mainland India

•  Himalayan North travel guide from Wikivoyage
• Resource Information Database of Indian Himalaya