Allow 3 hours for the trip.
Near the Bourtacombe Bridge, you’ll find a sign (1,719 m); follow the direction for Vallon de Varlossière. Shortly after the bridge, there’s another sign and the trailhead on the right, leading toward the Varlossière Valley and the Varlossière chalet. You’ll reach the lovely, lush Varlossière Valley and hike up to its summit. On a well-marked trail, you’ll first pass by the Varlossière chalets (1,920 m) (sign) and continue toward the Col du Châtelard. At the Col du Châtelard, you’ll find a sign (Croix d’Argentière—2,382 m); continue toward the Col du Bonnet du Prêtre.
This trail is marked with yellow signs.