Walkers on the Tour Du Mont Blanc cross a suspension bridge across the meltwater river from the Bionnassay glacier;

tour du mont blanc france alps french alps mountain mountain range weather rocks slope steep geology ridge erosion man walking group trek trekking exercise female male tour du mont blanc footpath long distance footpath outdoors fit fitness ascend mountain walking g friend 60's sixties river stream meltwater bridge suspension birdge vertigo crossing glacial meltwater bionnassay glacier