Park in the car park at the junction of the Névache D994G and Col de l'Échelle D1T roads.
(S/E) Take the latter. In winter, this road is shared by skiers, snowshoers and pedestrians. To avoid damaging it and allow everyone to enjoy the spot, take the line opposite the cross-country ski tracks.
Continue until you reach the junction with a track coming from Névache.
(1) Stay on the road, climb very slightly, pass the relay station and the telephone antennas. You will come out at the bend at the Chapel of Notre-Dame-de-Bon-Rencontre.
(2) Leave the road temporarily and take the snowshoe trail on the right. Take a detour through the woods to rejoin the road at the DCFI cistern. Stay on the road for a few metres.
(3) After the bend, turn right again into the woods and walk through the trees to return to the road at the hut on the left-hand side of the road.
(4) Return to the road and pass the customs officers' hut on the right-hand side of the road. At the bend before a small hill, you will reach a new crossroads.
(5) Leave the road again and follow the snowshoe trail. Make a very short climb before turning left to reach the metal mushroom of the Mauvais Pas blockhouse turret.
(6) Descend straight down through the snow to rejoin the road. Turn right to reach the tunnel entrance.
(7) Return via the Col de l'Échelle pass and stay on the road until you reach the car park where you started (S/E).