The balconies of the Valserine

The village of Chézery was built around the Cistercian abbey founded in 1140 by monks from Fontenay, in Burgundy. All that remains of the old abbey is the guesthouse which once provided shelter to pilgrims (now the Relais des Moines) and the parish church. The parish church was attached to the monastic church, which testimony from the time describes as being “big and beautiful”, with a nave with three aisles and six bays and a spire over the crossing of the transept. This closed off the cloister which, on the three remaining sides, served the abbot’s housing.

The “Following a legend” discovery trail, scattered throughout with many sculptures combining wood and stone, starts from the hamlet of La Rivière. It tells of this hamlet’s history, marked by the Roche France and the Troubléry stream, outstanding landscape features in this part of the valley (a booklet is available at the Chézery-Forens town hall).

South of the Reculet ridge, which reaches 1718 m in altitude, the High-Jura mountain range is cut through by a large depression that opens onto the valley of the Valserine. This type of erosion that affects a mountain’s summit or side is called a “combe”. The mountain’s structure shows a superposition of different limestone and marlstone layers, built up over tens of millions of years during the Jurassic period (-175 Mya to -145 Mya). At the foot of the cliffs, screes and landslides fill the heart of the combe, where erosion is still taking place.

The “Rocher des Hirondelles” (Swallows’ Rock) is an impressive limestone cliff with an airy shape on the edge of the Valserine. Here, the river has made a deep cut into the limestone and shaped this valley in the middle of the Mijoux-Chézery valley. This rock may well be named after the Eurasian crag martin, a master of flying on the hunt for insects, and a species that loves to nest in this type of cliff. This species, which was quite widespread in the Jura during the 19th century, has returned to the Massif since the 1980s.

In 2013, the Valserine became the first river in Europe to receive the “Wild river site” label. This label recognises the high quality of aquatic environments, and the little impact that human activity has had on the waterway and its catchment area. Created with the aim of protecting the less than 2% of rivers of exceptional quality and to eliminate the few black spots, this label led to a river agreement being signed in 2015. The morphological restoration of the waterway, the prevention of pollution by fuel tanks, the cleaning of illegal dumping and the fight against invasive plants are some of the main actions taken. 

As result of man’s pressing need to trade and travel, around forty structures bridge the distance over the Valserine and its small tributaries. Of these forty structures, some provide a wonderful opportunity to discover the valley and its landscapes. Just upstream from Mijoux, the natural bridge of La Giboulette is a limestone archway that was dug out by an adjacent stream. Downstream from Lélex, one of the oldest bridges - the Rouffy bridge - will allow hikers to follow the river at the bottom of the valley. Under Montanges, the Moulin des Pierres bridge was built as a tramway crossing in 1909 and overlooks the gorges: the view is dizzying! Finally, just before Bellegarde, you can still visit the old “Pont des Oules”, which was initially merely a limestone slab placed straight across the Valserine waterfall, and which was used by the Helvetii in 58 B.C.

The brown trout is a fish that is entirely suited to the Jura’s rivers, with their fresh and torrential waters. It has a slender fusiform body that is perfectly adapted to fast swimming. It feeds on the larvae of aquatic insects but also on small fish (including other trout!)

These ruins overcome by vegetation were once the vital core of a subsistence economy. It was to this mill, operated by the waters of the Valserine river, that the surrounding farms brought their grain. Thomas mill would turn barley and wheat into flour. The miller would keep twenty per cent of the production as payment for his work. Nearby, a sawmill complemented this activity.

As part of the wild river agreement, the Park and its partners are attempting to eliminate a tenacious invasive plant known as Asian knotweed. Every month, Asian knotweed plants are ripped out and taken to a special compost heap. Salt is scattered over its roots to attack the rhizomes that allow it to spread. The presence of Asian knotweed on the riverside is the result of the introduction of infested soil during landscaping works and of the re-mobilisation of rhizomes during floods. Never throw a piece of Asian knotweed root into water or on land, as it could grow back again.