At Martigny, where it receives the waters of the Drance on its left bank, the Rhône makes a sharp turn towards the north. Heading toward Lake Geneva (), the valley narrows near Saint-Maurice, a feature that has long given the Rhône valley strategic importance for the control of the Alpine passes. The Rhône then marks the boundary between the cantons of Valais (left bank) and Vaud (right bank), separating two parts of the historical region of Chablais. It then enters Lake Geneva near Le Bouveret, where the water flows west.