It soon becomes the boundary for a while between the departments of the HautesAlpes and of the Basses-Alpes, and receives successively the considerable Ubaye river, flowing from near the foot of Monte Viso past Barcelonnette (left), and then the small stream of the Luye (right), on which, a few miles above, is Gap. It enters the Basses-Alpes shortly before reaching Sisteron, where it is joined (right) by the wild torrent of the Busch, flowing from the desolate region of the Devoluy, and receives the Bleone (left) (on which Digne, the capital of the department, is situated) and the Asse (left), before quitting the department of the Basses-Alpes just as it is reinforced (left) by the Verdon, flowing from the lower summits of the Maritime Alps past Castellane.
7,858 Col de la Cayolle (Var Valley to Barcelonnette), carriage road 7,717 Col di Santa Anna (Tinee Valley to Vinadio), bridle path 7,605 Col del Sabbione (Tenda to Valdieri), bridle path 7,428 Col d'Allos or de Valgelaye (Verdon Valley to Barcelonnette), carriage road.
7,382 Col de l'Argentiere (Barcelonnette to Cuneo), carriage road.
8,855 Col de Sautron (Val Maira to Barcelonnette), bridle path.
One turning-point in the rivalry was the treaty of Utrecht (1713), by which France gave up to Savoy the districts (all forming part of the Dauphine, and lying on the Italian slope of the Alps) of Exilles, Bardonneche, Oulx, Fenestrelles, and Chateau Dauphin, while Savoy handed over to France the valley of Barcelonnette, situated on the western slope of the Alps and forming part of the county of Nice.