Follow the GR®9 to the Tunnel du Mortier, climbing via Plénouze

Meet at the Domaine de la Sure, at the Quoi chairlift car park, well below the resort itself.

(S/E) At the bottom of the car park, to the east, take the Route Forestière des Pichières, the only accessible road leading uphill.
Pass under the La Sure ski lift, then cross the ski run to continue along the forest road. This road has two hairpin bends and, 1,100 m further on (elevation 1,392 m), winds its way along the Font Chaude valley.

(1) Take a wide, steep path on your left heading northwards.

(2) Leave the forest track to the left of the Y-junction and continue climbing.
Keep a close eye out for the green markings topped with yellow on the trees.
After a 300-metre climb, you will find a path leading uphill on your right.

(3): Caution! Only a Green Cross and a Yellow Cross indicate that you should turn right, heading south. Follow this path, which crosses a few patches of nettles, to a tarmac road at the place called "Font Chaude – Alt 1540 m".

(4) On the other side of the road, take the cattle grating and continue your climb north-east, following the sign for “Plénouze 20 mins, 0.6 km” through a meadow.
The green markings topped with yellow are very rare, usually placed on the ground on barely visible stones. There are a few signs indicating the direction to follow: “Plénouze”.

(5) On reaching the hamlet of "Sous Plénouze - 1610 m", the path climbs straight ahead to reach Plénouze 200 m further on. At Plénouze, follow the sign for "La Sure - 55 min 2.9 km" to the next fork.

(6) Turn left heading north-west at the place called "Malatra - 1570 m" towards "La Sure 45 min 2.2 km"
Follow the wide forest track marked with the^GR®9trail signs (white and red), as well as the more visible signs featuring white snowshoes on a mauve background, until you reach the top of the Crêtes ski lift.
Stay on the path running furthest to the north-east to reach the La Sure viewpoint (signs point you towards La Sure – 1,643 m).

Once past La Sure, follow the^GR®9westwards towards “Près du Mortier”

(7). Here, there is an inaccuracy on the IGN map; the new^GR®9route runs slightly lower down towards “Près du Mortier – 15 mins and 0.8 km”.
Signposting is also sparse. You’ll need to look closely at the worn-down sharp limestone pavements to follow the path.

(8) On reaching "Près du Mortier - alt 1543 m", turn left onto the path leading down towards "Tunnel du Mortier - 20 mins km" and "Sous le pas - 5 mins - 0.3 km".
This path is not shown on the IGN map but is clearly marked and signposted in yellow and green.

(9) Cross the forest track and take the path opposite leading down towards "Sur le tunnel - 10 mins - 0.4 km".

(10) When you reach the spot known as "Sur le tunnel - alt 1410", turn left downhill and reach the tarmac forest road.

(11) Turn right towards "Tunnel du Mortier - 5 mins - 0.3 km". Follow the tarmac road to the ski resort reception building.
As shown on the map, you can take the final, gently sloping section of the ski run to avoid the last circular loop of the forest track.
Walk down the road until you reach your vehicle (S/E).

Alternative route:
(7) To avoid the area with sharp limestone pavement, as this is a section where you have to climb up and down a path that is difficult to navigate for hikers with inadequate equipment (especially footwear), you can follow the forest track and rejoin the route at (9).

Arrival at the car park: in summer, we recommend parking in the car park cut into the slope on your left as you arrive; your vehicle will be in the shade when you return in the afternoon.

A GPS is welcome but not essential for navigating the changes in direction during the ascent and then whilst following the^GR® between La Sure and the top of the Mortier Tunnel.

No water sources; a few tables are available at the top of the Crêtes ski lift and at the bottom of the Mortier ski lift for picnics. Please take your rubbish away with you; there are no bins. (But all hikers do this).

No known shelters.

Please note that the^GR®9from La Sure to the top of the tunnel requires high-top shoes (you will be crossing sharp limestone pavement). The red and white markings are relatively scarce here, so look carefully at the wear on the ground to find your way without a GPS.
A forest track allows you to avoid this section.
Similarly, the second part of the climb towards Plénouze has a few areas with stinging nettles; it’s best to wear trousers to cross this section.

Cattle grid: open to pedestrians; cattle cannot cross the round bars with the gap below.

The author would like to point out to those keen on scenic viewpoints that the path is usually some distance from the ridge edge. Viewpoints are rarer here than elsewhere. The first viewpoint is located just before La Sure. Then a few gaps in the vegetation allow you to see the imposing cliffs above Le Mortier.

From Plénouze, you can head south via the Sentier des Génisses to reach La Molière, another lovely hike.

Both Autrans and Méaudre are quiet villages worth visiting after the hike.
La Ferme des Colibris in Méaudre, in the hamlet of Les Arnauds, is easy to visit. You’ll meet friendly farmers raising animals in an ethical manner.