Réserve naturelle nationale des Contamines-Montjoie, National nature reserve in Haute-Savoie, France

The Réserve naturelle nationale des Contamines-Montjoie is a protected area stretching from about 3,600 feet (1,100 meters) to nearly 12,800 feet (3,900 meters) at the Aiguille de Tré-la-Tête. This elevation change creates multiple distinct environments, from dense spruce forests at lower levels through open alpine meadows to glaciers and rocky zones at the summit.

The idea of protecting the site emerged around 1972, during preparation of the first land-use plan, when local officials chose to limit building in the valley floor, allow measured use of the ski area on the left bank of the Bon Nant and keep the opposite bank undeveloped. A public inquiry followed in 1976 and the reserve was created by decree in 1979. The association Les Amis de la Réserve Naturelle des Contamines-Montjoie was founded in 1983.

The reserve takes its name from the village of Les Contamines-Montjoie, in the Val Montjoie at the foot of the Mont-Blanc massif. A Roman road from Notre-Dame-de-la-Gorge crosses the reserve and now carries the GR5 and Tour du Mont-Blanc long-distance paths. The Maison de la Réserve in the village presents the reserve's history, geology and wildlife.

About 70 km of trails cross the reserve, which has three mountain refuges: Les Conscrits, Tré la Tête and Les Prés. The reserve runs from the banks of the Bon Nant at 1,100 m up to the Aiguille de Tré la Tête at 3,892 m, so paths climb through several climate zones. The valley is oriented north-south, and snow can lie at 1,165 m for 117 days a year.

The reserve's 5,500 hectares span the largest elevation range of any French nature reserve, from 1,100 m on the Bon Nant to 3,892 m at the Aiguille de Tré la Tête. The Col du Bonhomme, in its southern part, marks the contact between the Mont-Blanc crystalline basement and the folded Alpine sedimentary cover, a site used to read the massif's geological history.