Nanda Devi Sanctuary

The park encompasses the Nanda Devi Sanctuary, a glacial basin surrounded by a ring of peaks between 6,000 metres (19,700 ft) and 7,500 m (24,600 ft) high, and drained by the Rishi Ganga through the Rishi Ganga Gorge, a steep, almost impassable defile. The entire park lies at an elevation of more than 3,500 m (11,500 ft) above mean sea level.

The Sanctuary can be divided into two parts, Inner and Outer. Together, they are surrounded by the main Sanctuary Wall, which forms a roughly square outline, with high, continuous ridges on the north, east, and south sides. On the west side, less high but still imposing ridges drop from the north and south toward the Rishi Ganga Gorge, which drains the Sanctuary towards the west.[4]

The Inner Sanctuary occupies roughly the eastern two-thirds of the total area, and contains Nanda Devi itself and the two major glaciers flanking the peak, the Uttari (north) Rishi Glacier and the Dakshini (south) Rishi Glacier. These are fed by the smaller Uttari Nanda Devi and Dakshini Nanda Devi Glaciers respectively.[4] This region was already inhabited by the aryanic, Mongolian and Himalayan indegenous peoples as per vedas and natural history but the first recorded entry of Britishers into the Inner Sanctuary was by Eric Shipton and H. W. Tilman in 1934, via the Rishi Gorge.[5]

The Outer Sanctuary occupies the western third of the total Sanctuary, and is separated from the Inner Sanctuary by high ridges, through which flows the Rishi Ganga. It is split in two by the Rishi Ganga; on the north side lies the Ramani Glacier, flowing down from the slopes of Dunagiri and Changabang, and on the south lies the Trisul Glacier, flowing from the peak of the same name. This portion of the Sanctuary is accessible to the outside (though requiring the crossing of a 4,000 m (13,000 ft) pass). The first serious climbing expedition to pass through the Outer Sanctuary was that of T. G. Longstaff, who climbed Trisul I in 1907 via the eponymous glacier.[5]