The French département Hautes-Alpes is marked by mountains and wild ranges.
The Hautes-Alpes are easily reached by train from either the south (Marseille), the north (Grenoble) or the west (Valence). Valence and Grenoble have high-speed train connections with Paris. There are up to four train connections daily in all directions.
There is no large airport in the Hautes-Alpes. Go to Marseille and take the train from there.