Starting at Fouillouse. Access from Saint-Paul-sur-Ubaye on the D25. After 3 or 4 km, near Pont du Châtelet, take the small road to the right, which after a few bends, leads to Fouillouse. Just before the hamlet, the car park is a bit higher to the left of the road.
(S) Go through the hamlet heading east and passing the cemetery.
(1) A few dozen metres after the last houses, take the trail heading to the left, due north which rises over the road (sign for "Refuge du Chambeyron"). The trail turns off to the left maintaining a north-west direction.
(2) At a junction just outside a wooded area, turn right at an acute angle. Head north-east with a few twists and turns within a landscape which gradually gets lighter.
(3) Turn right heading east. There are no more trees and the landscape is more mineral. It's a windy trail but keeps to an overall eastern direction.
(4) Directly below a mound of rock to the left, you'll get to a small pass and a view point over Lac Premier and Refuge du Chambeyron (easily spotted due to its blue metallic coating). Head down to the shelter.