The Indian Himalayas run mostly through the states of Jammu & Kashmir, Himachal Pradesh, Uttranchal , Sikkim , and Arunachal Pradesh.

They can be divided into four zones running parallel to each other. These zones are determined by elevation and geological age.

1. The Sub Himalayan (Outer) Zone, the Siwalik foothills - 5 to 50 km wide, their altitude rarely exceeds 1500 meters above sea level. This region is generally covered with damp forest.
2. The Lesser Himalayan (Central) Zone - 40 to 80 km wide, their altitude averages about 3050 meters above sea level. A number of Hill resorts are located in this region. The lower slopes have magnificent forests of chir, deodar, blue pine, oak and magnolias. Above 2450 meters there are woods filled with birch, spruce and silver fir.
3. The Great Himalayan Zone - the oldest of the zones, this about 160 km from the edge of the plains. It consists of a lower alpine zone up to 4875 meters above sea level and an upper snow-bound zone over 4575 to 5100 meters above sea level. The latter has a large number of the world's highest peaks including the three highest ( Mount Everest , K2 and Kanchendzonga). The alpine zone has rhododendrons and thick shrubs with variety of beautiful flowers and grass. The upper snow-bound zone has rare medicinal herbs.
4. The Trans Himalayan Zone - About 40 km in width, this encompasses the valleys of the rivers rising behind The Great Himalayan Zone, at an altitude of 3600 to 4250 meters above sea level.