The Cordillera Huayhuash (possibly from Quechua waywash weasel) is a mountain range within the Andes of Peru, in the boundaries of the regions of Ancash, Lima and Huánuco. Since 2002 it is protected within the Cordillera Huayhuash Reserved Zone.
The Huayhuash range is 30 km long north to south and includes seven peaks over 6000 m including Yerupajá which, at 6,617 metres (21,709 ft), is the second highest peak in Peru. Another notable peak, Siula(6,344 m) was made famous by mountaineer Joe Simpson in his book Touching the Void. Unlike neighboring Cordillera Blanca, Huayhuash doesn't possess broad valleys and mountain passes are higher. There are many lesser peaks surrounding those covered by ice, and several passes exceeding 5,000 m. It is necessary to travel a considerable distance from the central range to find ground lower than 3,000 m, even on valley floors, and the range is often taken to include this much larger area. The vegetated areas of the range are part of the Central Andean wet puna ecoregion.