When the Compagnie Nationale du Rhône (CNR) established hydroelectric plants at Belley and Brégnier-Cordon, the locks built at Chautagne and Belley made the river navigable again as pleasure boats and passenger craft could travel beyond the factories of Lavours and Brens-Virignin.
Over 60 km of the Upper Rhône became accessible to visitors, who can now admire many different natural habitats that harbour a wealth of plant and animal life.
Extending 25 km from the south of Bugey to the Dauphiné, the 1,707-hectare Upper Rhône Nature Reserve is France’s largest alluvial forest reserve.