Réserve naturelle nationale de la tourbière de Machais

Réserve naturelle nationale de la tourbière de Machais is one of the most ecologically significant sites in the Vosges massif — a national nature reserve protecting the last and largest floating peat bog surviving in a near-intact state anywhere in this mountain range. The reserve sits in the commune of La Bresse, in the Vosges department of the Grand Est region, occupying a glacial cirque along the ridge that connects the Col de Bramont to the Rainkopf summit.

Where exactly is the reserve located?

The protected area stretches along the so-called Route des Américains (road D.34a), which links the Col de Bramont pass to the Rainkopf peak. This ridge-top setting, surrounded by the rounded summits and forests typical of the Vosges, makes Machais both a geologically remarkable site and one that remains fairly accessible to hikers.

When was the reserve created, and how large is it?

The reserve was established in 1988 and covers a total area of roughly 145 hectares. Of this, 25 hectares are occupied by the peat bog itself, while the remaining 120 hectares consist of forest surrounding the wetland core. This layout — a small but exceptionally valuable peatland heart wrapped in a forested buffer zone — helps protect the fragile ecosystem from outside pressure, including erosion of the bog's edges and excessive foot traffic.

Why is this peat bog so unusual?

Machais belongs to the rare category of floating peat bogs (French: tourbière flottante), whose surface partly floats on water, creating an unstable, waterlogged, and highly fragile environment. This is precisely why it is regarded as the last such well-preserved example of this type of habitat anywhere in the Vosges. Floating bogs form over hundreds or even thousands of years, as peat-forming vegetation gradually builds up on the surface of glacial lakes — which explains why one survives here, cradled inside the Machais glacial cirque.

How rich is the reserve's biodiversity?

The scale of biodiversity recorded within the reserve is striking: researchers have identified a total of 1,304 animal and plant species here. These include 712 species of plants and fungi, 255 insect species, 214 flowering plant (angiosperm) species, 113 moss species, 72 arachnid species, 37 mammal species, and 33 lichen species. This concentration of taxonomic diversity within a relatively small area confirms Machais's status as one of the biological hotspots of the Grand Est region.

Can visitors explore the reserve?

Yes, though with one important restriction. Marked hiking trails cross the reserve year-round, allowing visitors to take in the glacial cirque landscape and the surrounding forest. However, entry into the central peatland — delimited by the Tour de l'Étang trail — is strictly prohibited at all times, with no seasonal exceptions. This rule exists to shield the most fragile, floating part of the ecosystem from irreversible damage caused by trampling.

Frequently asked questions

Can visitors bring dogs or bicycles into the reserve? The available sources do not specify detailed rules on pets or bicycles — it is worth checking the current regulations on site or with the reserve's management before a visit.

How does the reserve compare in size to other Vosges peat bogs? With a total area of 145 hectares, of which 25 hectares form the bog itself, Machais is considered the largest surviving floating peat bog in the entire Vosges massif.

Is the reserve open year-round? The hiking trails remain open throughout the year, while the central peatland stays off-limits regardless of season.

Who manages the reserve? The reserve falls under the oversight of the nature conservation authorities of the Grand Est region, as part of the network of nature reserves within the Ballons des Vosges massif.