Devil's Bridge Gorges

Deep in the valley of the river "Dranse de Morzine" in the village "La Vernaz" a interesting place is located. The "Devil's Bridge Gorges" is s gorge in the french alps, which is accessible for visitors.

The gorge, properly said, is the result of the slow erosion caused by the "Dranse de Morzine", which has gradually cut into the rock like a knife. This erosion, which took tens of thousands of years, mainly occurred during the melt of the last Great Glaciers which covered the Alps. At the time the flow of the torrent could be much more powerful than it is today. This explains the importance of the erosion: the gorge reaches a depth of 60 metres. The difference in level between the road and the river is 120 metres. It is the force of the torrent that has dug out these enormous cavities you can see along the walls. These are very rapid whirlpools which sweep away the sand and shingle that dug them out: They're called "giants' kettles".

In the galleries of the gorge, covered over several dozen metres of piling blocks the "Dranse" has continued its work of erosion. Yet the "Dranse" has cut his way through a very resistant marble-like rock; it is grey, white veined; but the walls have been covered with a 2 - 5 centimetre thick deposit by the surface water and have been coloured brown and green by metal oxydes and salts. In former times red and green marble was extracted from the "La Vernaz" quarry, a village 2 kilometres from the gorge.

Because the rock is a compact and resistant rock, the walls have remained the way the river had sculpted and polished them. When the rock is more crumbly, they are worn away by the effect of the frost and surface water.

Deep in the gorge an enormous block, forming an arch above the "Dranse" is itself also a collapsed rock; it is the one people call "Le Pont du Diable" (the Devil's Bridge). Once it was used to cross the river by the habitants of Le Jotty and La Forclaz, who used to take the path you can still distinguish on the side of the rock. This short-cut saved them a 4-kilometre detour via the Bioge bridge.

The green colour of the water outside the spate periode is due to the profileration of a microscopic moss which remains in suspension and gives the characterisitc green colour to mountain lakes.