The Dragon under the Rock

Comprised of four arches, with one measuring eighteen metres and three other smaller ones, the Tram bridge crosses the Volferine river near the new Pont d’Enfer (Hell’s bridge). On the old tram line that linked Bellegarde-sur-Valserine to Chézery-Forens, it is one of the three bridges built for the tramway’s passage after that of Bellegarde and the Pont du Moulin des Pierres, which overlooks the gorges from 65 metres high with a range of 80 metres.

Telemechanism is a principle that rapidly declined with the emergence of electricity. The pillars are remnants of a time during which an abundance of ideas on technical improvements flourished. These cut-stone pyramid-shaped pillars provided support to one or more wheels, built into the upper part. The cables ran from the pulley, driven by the turbine (located further downstream), before running around the pillar’s wheels and reaching the grain mill wheel, which in turn activated the grinding wheel by a series of gears.

The Valserine is the first French river to be labelled a “Wild River”, a label that less than 1% of French rivers are able to claim... From its source to its end in Bellegarde (46 km), its condition close to a natural state makes this river a jewel of nature. Many emblematic species are present: the yellow-bellied toad, large populations of brown trout in a good condition of preservation, all completely natural... Since 2015, a wild river contract leads actions to ensure the free circulation of fish and sediments, to rehabilitate wetlands near waterways, to eradicate invasive plants, to eliminate former riverside landfills, etc. Find out more:  www.rivieres-sauvages.fr/ www.parc-haut-jura.fr/fr/site-habitant/gestion-environnement/zones-humides-rivieres/valserine-riviere-sauvage.263-280-1104__1623.php

Between this succession of high walls, Dragon’s bridge, built in 1891, only has a few metres to span to cross the river. A customs guard house was installed on the right bank to monitor the passage towards the duty-free zone in the Pays de Gex, delineated by the Valserine. On the other bank, a shop offered colonial goods and products from the duty-free zone up until 1921. The inhabitants of Champfromier tell of how their parents or grand-parents would walk to the Dragon’s farm, where duty-free coffee was sold. The game was to hide illicit products under the women’s skirts, away from customs officials. Smuggler’s tales are now part of local folklore.

The Sous-roche dam upstream from the Dragon’s bridge was installed between the two world wars on the Valserine, straddling the municipalities of Chézery-Forens and Champfromier, to use the water’s hydroelectric power. A fish pass positioned on the left embankment allows trout to cross the obstacle. However, the structure limits the circulation of sediments dragged along by the river. Under the Wild River contract, solutions are being studied to improve the transportation of sediments, which is vital for the proper operation of the river.

The electrical equipment for the tramway line was entrusted to the company Thomson-Houston. It was the first tramway in the Ain to be completely electric as from its construction. The plant required the construction of a dam, a 900-meter supply line, a steel and concrete penstock that fed, after a 40-meter drop, its two direct-current generators. The plant is still in use; it is automatically controlled from the Génissiat dam. The first storey, with access from the side of the building, was reserved for the housing of power plant guards.

Taking care to stay on the path, through the trees, you will see a tufa waterfall. Upstream, during its underground travels, the water from this rivulet has dissolved part of the limestone. In open air, on contact with carbon dioxide (CO2), the limestone transported by the water settles on and calcifies the moss and other debris forming this curious rock with the treacherous appearance of a sponge or of volcanic rock.