After a relatively calm and wide first part down to Ristolas in the Hautes-Alpes department, the Guil is fed by around fifty tributaries. The Ségure in Ristolas, the Bouchet in Abriès, the Lombard in Aiguilles, the Aigues in Château-Ville-Vieille, or the Cristillan at Maison du Roy contribute to its nature as a torrential river. Between Maison du Roy and Guillestre, the Guil crosses impressive gorges revealing the power of its flow and feeds a dam. It comes out of the valley that it has sculpted into a canyon at the height of Font d'Eygliers, where it finds a more peaceful course.