Sierra del Chachil, Mountain range in Neuquén Province, Argentina.

Sierra del Chachil is a mountain range in Neuquén Province that extends from Pino Hachado Pass to Cerro Las Lajas. The highest peak reaches 2,839 meters (9,331 feet), with notable summits such as Atravesada, Queli Mahuida, and Palau Mahuida surrounding lakes Alumine, Moquehue, and Ruca Choroy.

The range's name comes from the Günün a küna language: chüüyü a chül, 'stone of the turn'. Travellers passing the Chachil stone turned around it while praying and leaving an offering for a safe journey; it is also called 'Piedra del río Charahuilla'. The sierra runs from Cerro Chachil (2,839 m) to Cerro Las Lajas, with Atravesada, Queli Mahuida and Palau Mahuida between them.

Chachil derives from the Günün a küna language, from chüüyü a chül, 'stone of the turn'. Travellers passing the site had to walk a turn around the altar stone while praying and leaving an offering for a safe journey and good fortune. It is also known as the 'Piedra del río Charahuilla'.

The range is accessible via National Route 40, with the towns of Zapala and Alumine serving as main starting points for mountain activities. From these locations, visitors can plan hikes and explore the multiple lakes in the area.

The range's name comes from the Günün a küna language: chüüyü a chül, 'stone of the turn'. Travellers passing the altar stone walked a circle around it while praying and leaving an offering for a safe journey. It is also known as the 'Piedra del río Charahuilla'.