Harsil is a village and a cantonment area, on the banks of Bhagirathi River, on the way to Hindu pilgrimage, Gangotri, in Uttarkashi district of Indian state of Uttarakhand). Situated at a height of 7,860 ft (2,620 metres.) from sea level, Harsil lies 73 km. from Uttarkashi, and 30 km away from Harsil, lies the Gangotri National Park, spread over 1,553 square km.
Delhi-Hardwar-Harsil Ridge (DHHR), the basement ridge is a northerly extension of the Aravalli Mountain Belt, which also trends in a NNE-SSW direction and stretches from Amba Mata-Deri (Gujarat-Rajasthan) to Delhi via Ajmer and Jaipur.
Over the years, a small number of Jadhs, an ethinic group of the Bhotiyas, have settled here, and speak a language closely resembling Tibetan.
The idol of the Hindu River Goddess Ganga (Ganges) is brought down from the shrine at Gangotri in the upper Himalayas after Diwali and kept at 'Mukhba' village near Harsil. It remains there throughout the winter when Gangotri is snowbound and inaccessible.
Defence Agricultural Research Laboratory:
A detachment of the Defence Agricultural Research Laboratory run by the Defence Research and Development Organisation (DRDO), was established here in May 1973.