One half of the "Train Jaune" journey is travelling along the valley of the "La Têt" river, starting in Villefranche-de-Conflent at 427m for reaching 30km later the highest point at Bolquère at 1592m. No rack or other help is given for doing this, so the line is most if the time climbing in a 60 one-tenth of a percent grade. Short after the station of Sauto the line is crossing the valleys main road.
