The borders of all three countries converge at a tripoint near the summit of Mont Dolent at an altitude of . From here the French - Italian border runs southwestwards along a ridge of high summits on the southern side of the massif, many of which are over in height, including the Grandes Jorasses, Rochefort Ridge, Dent du Géant, Mont Maudit, Mont Blanc and its western satellite, the Aiguille de Bionnassay. From here the border turns southwards over the Dômes de Miage and Aiguille de Tré la Tête before dropping down to the Col de la Seigne. North of Mont Dolent the border between France and Switzerland meanders roughly north-northwestwards along a ridge-line of slightly lower peaks, including the Aiguille d'Argentière, the Aiguille du Chardonnet and the Aiguille du Tour, before dropping down to the Col de Balme. The Swiss - Italian border runs southwest from Mont Dolent, down to the twin passes of Col Ferret.