Parking is available at the starting point but spaces are limited. We followed the white/green horizontal markings for most of the route. At the signposts, we followed "Saint Hilaire la Croix", "La Sep" and "Barrage de la Sep".
(S/E) Cross the dam bridge and, at the end of the bridge, turn right and continue for about 100 metres on the road you came from by car.
(1) Leave the road and turn right onto the path that leads into the forest and follow the horizontal white/green markings. Follow the lake on your right and join the Ruisseau des Riaux.
(2) Continue along the lake and join the Sep, which feeds into it.
(3) Continue around the lake until you reach the junction with the Combe de la Lèbre.
(4) Ignore the road on your left and continue along the lake to reach the dam car park (S/E).