During and after the 1950s, when India began patrolling this area and mapping in greater detail, they confirmed what the 1914 Simla agreement map depicted: six river crossings that interrupted the main Himalayan watershed ridge. At the westernmost location near Bhutan north of Tawang, they modified their maps to extend their claim line northwards to include features such as Thag La ridge, Longju, and Khinzemane as Indian territory. Thus, the Indian version of the McMahon Line moves the Bhutan-China-India trijunction north to 27°51’30"N from 27°45’40"N. India would claim that the treaty map ran along features such as Thag La ridge, though the actual treaty map itself is topographically vague (as the treaty was not accompanied with demarcation) in places, shows a straight line (not a watershed ridge) near Bhutan and near Thag La, and the treaty includes no verbal description of geographic features nor description of the highest ridges.