The GR® 9 begins in St-Amour 39. In the department of Ain, it goes all over the oriental crest, by Colomby de Gex, goes through the gap Nantua-Bellegarde, visits plateau de Retord and goes through Grand-Colombier, before diving in the Rhône valley.
Free access (weather depending)
- Distance : 100.1 km
- Level black - very hard
Free of charge