Depart from Vailly, at a place called La Côte. Pass La Côte-d'en-Haut and park at the intersection of the road and a forest track, before the "Impasse" sign (parking spaces are available on the sides of the road or forest track).
Directional signs are present at all major intersections. Most are old and made of wood, others are more recent and made of modern materials.
Without signposts
There are a few old markers, which are only indicated here when necessary.
(S/E) Follow the forest track towards Notre-Dame d'Hermone. Climb steadily, passing La Grange au Riond on your right, until you reach a hairpin bend to the left.
(1) Continue along the track, turning left towards Le Plansuet/Hermone. Ignore two paths, one uphill on the right and one downhill on the left. At a fork, take the steep, stony path on the right.
(2) Exit the forest and climb more gently to the Plansuet chalets. Go through a gate and pass between the chalets. Pass a drinking trough on your left, then a tree with a yellow marker on your right. Go through a second gate.
(3) When you exit the gate, head straight ahead, due south, across a pasture (there is no path here; the IGN map is inaccurate). Aim for a patch of meadow to the right of a group of spruce trees and you will find a trail. Turn right towards a signpost. Then turn right towards Notre-Dame d'Hermone, follow the tracks along a fence and quickly veer off to the right to find a well-marked path (red round markers). Follow the path to the ridge path.
Red and white markings + signposts with yellow arrows
(4) Follow the path up to the left, passing a superb viewpoint over Lake Geneva (on the right) and quickly arriving at the Hermone Chapel.
(5) Retrace your steps to the intersection.
(4) Continue straight ahead on theGR® Balcon du Léman trail, which follows the Mont d'Hermone ridge in a north-easterly direction. Descend slightly, ignore a path on the right towards Les Combes, then climb back up through the forest. Pass a flat area on the right (view of Mont Billiat) then descend slightly again. Ignore a faint path on the right and climb steeply to reach the summit of Mont d'Hermone.
(6) Continue north-east towards Montagne des Soeurs. Descend, alternating between steep and gentler slopes. You will come to a crossroads marked by a sign saying "Altitude 1260m".
(7) Continue straight on towards Montagne des Soeurs. A few metres below, at a fork, turn right towards Reyvroz (main town) and cross a fence to reach the Montagne des Soeurs mountain pasture. Quickly leave the path to reach the highest point of the pasture on the right, where there is a sweeping view of Lake Geneva.
(8) Retrace your steps to the sign marked "Altitude 1260m".
Yellow markings (usually in the form of a circle)
(7) Take the path on the left towards Vailly/Reyvroz. After a few metres, at a fork, take the right-hand path towards Vailly-La Côte. Heading south-south-west, follow a narrow, poorly marked path downhill, surrounded by vegetation in areas where trees have recently been felled, but better marked under dense forest cover. Be careful not to lose this path and follow the markings, which are conveniently dense on this section.
(9) At signpost no. 32, continue straight on towards Vailly (note that this path and the one leading left towards Palatieu are both marked in yellow). After a short stretch on a narrow path through the vegetation, you will come to a wider path, which you should follow to the right. At signpost no. 31, turn right towards Vailly and you will reach a crossroads (signpost no. 30).
(10) Then take a steep, stony path heading south (note that all the paths here are marked in yellow). Walk along the edge of the forest on your left and a recently cut plot on your right. At a fork (not shown on the IGN map), turn left down a steep slope. Cross a path (not shown on the IGN map) and descend to the forest track taken at the start of the hike.
No markings
(1) Follow the forest track to the left and return to the starting point (S/E).

