Drive from Valernes to the main Sisteron-Gap road and head north. Before Gap, take the Tallard turning to the right and follow the signs for Briançon. After crossing the lac de Serre-Ponçon, keep going until you reach Embrun. Take a left in the middle of the town, following the signs to a small commune called Calayère. Continue along this road for several more kilometers until you reach a car park at 1587m.

 

A number of walks are available at this point. Ours follows a forest track that leads off to the right and which, after a few minutes, passes the refuge of Fontaniers. The tracks are well-signposted and you should follow the ones that direct you to the chapelle de Séyères by the Widman path. Before reaching Pre Clos, you will be directed off the forest track and onto a narrower but well-marked walker's track. This leads through fir trees up to the chapelle de Séyères at an altitude of 2056m.

The next part of the walk should not be attempted during the winter and spring, unless you are well-equipped with winter walking equipment. Some of the paths, even in late October, may be covered in ice and can be very slippery. The walk continues from the chapel, past a fountain and into another wooded area. Watch out for a sign that will direct you to the right up the sentier Widman towards Mont Guillaume.

 

The forest is left behind as the track continues to climb against the north-eastern face of Guillaume in a series of diagonal traverses. There is one ambiguous junction; at a fork, one track climbs steeply to the left and the other passes around a large, square boulder to the right before turning away out of sight. The second path is the correct one to follow. The path then climbs steadily until the chapelle de Guillaume (2552m) is reached. This is a superb place to rest and enjoy the view, all the way from Guillestre to the east, over the lake to mountains of Morgon and Dormillouse, and to the south as far as the Chanderettes and the other mountains of the pre-Alpes of Digne.

 

If you wanted to, you could rest here happy in the knowledge that you have enjoyed an excellent walk and you may signal your pleasure by making a note in the Livre d'Or, kept inside the chapel for such purposes. However, the summit of Guillame (2623m) is only a few tens of metres away and by following the ridge to the north-west you could soon be there. The views to the north are excellent and include the often snow-capped le Mourre Froid.

 

To return, either retrace your steps or, at the chapelle de Guillaume, take a steeply descending path facing the town of Embrun. This rejoins the up-bound track at the aforementioned ambiguous junction, and saves about 20 minutes of extra walking (so allowing more time at the summit!). The remainder of the descent follows the same route as that used on the outbound leg.