The Romanche is a 78-kilometre (48 mi) long mountain river in southeastern France, right tributary of the Drac (itself a tributary of the Isère). Its source is in the northern part of the Massif des Écrins, Dauphiné Alps. It flows into the Drac in Champ-sur-Drac, south of Grenoble. The road from Grenoble to Briançon over the Col du Lautaret runs through the Romanche valley.