The Hindu Kush-Himalayan (HKH) Mountains in South Asia constitute one of the most robust ecosystems on planet Earth. Many of the environmental crises the planet earth is in the grip of are attributable to the very state of 'ecological coup' the HKH Region appears to be at the verge of. The traditional ecological knowledge has been potent source of the marginal mountain communities to derive inspiration from and articulate into the processes of sustainable mountain development. The traditional ecological knowledge of the people in the HKH Region is rooted into ecosystem realities, is enveloped in an eco-philosophy, holds reverential attitude towards nature and nature's components, and embraces a world view of its own. Evolved by local people over millennia through trial and error, the traditional knowledge is dynamic, compassionate, caring, transcendental and futuristic, and evolves continuously and unceasingly in tune with time and space. This volume is an effort to look into the pristine and also somewhat forgotten traditional knowledge systems in the fragile mountains of the HKH Region. Written by many eminent mountain scholars from many countries, the various chapters in the volume would surely contribute to recognise, enrich and articulate the traditional ecological knowledge and further help restore and promote the systems based on this knowledge.