(S) Start from Chalet ECIR, Route du Sancy, and head up towards the resort. Look for the small mountain path that starts from a blue trail (I had a little trouble finding it) and follow it.
(1) Pass under the chairlift at the source of the Dordogne.
(2) Once on this path, after crossing a stream, take the path that climbs steeply up the mountain and follow it to the top to take the stairs that lead to the top of Sancy.
If you wish, before turning right and climbing the mountain, you can follow the path to admire the Dore waterfall.
(3) At the top of the Sancy, continue straight on theGR®30to the Col de la Cabanne. Please note that this is a very technical trail.
(4) At the Col de la Cabanne, take theGR®4(do not follow "Vallée de Chaudefour").
(5) On theGR®4, follow the signs for Chambon-sur-Lac until the next junction.
(6) At this junction, leave theGR®4and follow the ridges until the trail descends. Continue downhill until you reach the nature reserve, which is accessible via a small ladder.
(7) Go up the small ladder and follow the path to the left and then to the right (north-east direction), descending the switchbacks until you pass two barriers.
(8) After the second gate, take the first path on the right until you reach the road, cross it and take the path opposite.
(9) Once on this path, turn right then left until you reach the next road (D36), cross it again and pass through the hamlet of La Guièze.
(10) At La Guièze, keep right and go down the path that leads to Voissières (campsite).
The Voissières relay point is located right next to the campsite (E).