The 1860 act and attached maps are still legally valid for both the French and Italian governments. One of the prints from the 1823 Sarde Atlas positions the border exactly on the summit edge of the mountain (and measures it to be high). The convention of 7 March 1861 recognises this through an attached map, taking into consideration the limits of the massif, and drawing the border on the icecap of Mont Blanc, making it both French and Italian. Watershed analysis of modern topographic mapping not only places the main summit on the border, but also suggests that the border should follow a line northwards from the main summit towards Mont Maudit, leaving the southeast ridge to Mont Blanc de Courmayeur wholly within Italy.