Following a rocky landslide at a place called Le Claps in 1442, the flow of the Drôme was barred and a large lake was formed. Dry in the 19th century, today only the Bouligons marsh remains, which is one of the last wetlands of Haut-Diois. Located on the commune of Beaurières, its surface is of 65 ha. The Department of Drôme acquired it between 1994 and 1998 to create a Sensitive Natural Area where remarkable species of fauna and flora rub shoulders. A marked path has been laid out thanks to gratings. So the marsh can be visited on foot while respecting fragile environments. From the parking of the D93 regional road, the discovery trail makes a loop of 3 kilometers with a vertical drop of 100 meters. From the village of Beaurières, the round-trip hiking trail is 12 kilometers long and 350 meters high.