The Outer Himalaya are also referred to as the Himalayan Foothills and are called Siwalik Hills. They rise to 2000m above sea level and are chiefly composed of sandstone and conglomerate rock formations. They are enriched with vast biodiversity as the major rivers and their tributaries create unique micro-eco zones.

Large areas of the Himalayan foothills are covered with Tropical and Subtropical Broadleaf forests. The rich diversity of soil and varying rainfall across the Siwalik hills, make it possible for evergreen, mixed deciduous, wet and dry tropical forests to flourish in their region. These dense forests are home to tigers, elephants, and more than 300 species of birds amongst a wide variety of species.

Relatively speaking because of their lower altitudes, the Siwaliks are also the most accessible and well-populated part of the Himalaya. They are home to several major towns and boast massive tourist footfalls.

When we begin our climb upwards from the Siwalik ranges, we encounter the Lesser or Lower Himalaya. They rise from 2200m to 4000m above sea level and are also called the “Himachal” or “Inner Himalaya.” Their southern slopes are sharper than their northern ones which are covered by mixed forests of deciduous and coniferous trees. These high-altitude forests comprise evergreen trees such as Oaks, Birch, Horse Chestnut, Cherry and Rhododendrons. They attract more than 500 species of birds and are home to animals such as Leopard, and the Golden Langur.

A mix of monsoon rains, melting mountain snow and glacier-fed riverbeds create a unique ecology for both forests and agriculture to flourish. Driving by settlements both small and large, one can spot hundreds of terraced fields with paddy, maize or vegetables. Orchards of citrus, plum and apples gently traverse across the slopes.

Many well-known hill stations such as Binsar, Tawang, and Shimla fall under the Lesser Himalayan region.

As the forested slopes of Inner Himalaya give way to the rising altitudes of the Greater Himalaya, the air becomes thinner. Also known as the “Himadri” the Greater Himalaya rise from 4000m to 8000m plus. The backbone of the Himalayan orogen, the Greater Himalaya, also called “Higher Himalaya”, encompasses several of the world’s highest peaks including Nanga Parbat, Nanda Devi, Annapurna, Mount Everest, and Kanchenjunga. But even though forever covered in snow, the Himadri is not at all barren.

As the elevation rises, the treeline in the Himadri transitions from the forested Himalayan ecoregions to the alpine and sub-alpine ecology. The alpine forests higher up open into alpine grasslands and lush alpine meadows culminating in scrublands in the highest peaks, leading to the permanent snowline. A wide variety of flora is found here in the summers along with evergreen conifer forests. The Red Panda, Musk Deer and the elusive Snow Leopard call the Greater Himalaya their hearth.

Due to snow, higher altitudes and lack of all-weather road connectivity many of the Greater Himalaya mountains have sparse and spread-out populations. Agriculture and pastoral livelihoods are the anchors for these remote communities.

The monsoon-loving Eastern Highlands, widely referred to as the “Purvanchal”, cover most of India’s North-eastern states. The predominantly wet climate of the Purvanchal encourages diverse vegetation from tropical evergreen to temperate evergreen and coniferous forests. Its impenetrable bamboo thickets are home to the Tiger, Panther, Himalayan Bear. A wide variety of birds, both, native and migratory, are found in vast numbers.

Several tribes and clans with distinct traditions call the Purvanchal mountains their home. India’s Northeast states are rich in cultural diversity and people of the eastern mountains are firm believers in the collective power of community.