evidence: The Kalapani territory is an area under Indian administration as part of Pithoragarh district in the Kumaon Division of the Uttarakhand state,[4][5] but it is also claimed by Nepal since 1997.[6][7] According to Nepal's claim, it lies in Darchula district, Sudurpashchim Province.[8] The territory represents part of the basin of the Kalapani river, one of the headwaters of the Kali River in the Himalayas at an altitude of 3600–5200 meters. The valley of Kalapani, with the Lipulekh Pass at the top, forms the Indian route to Kailash–Manasarovar, an ancient pilgrimage site. It is also the traditional trading route to Tibet for the Bhotiyas of Kumaon and the Tinkar valley of Nepal.[9][10] [...] No changes in India's border with Nepal are discernible from the maps of the period.[55] The Kalapani territory continued to be shown as part of India. Following the Chinese take-over of Tibet in 1951, India increased its security presence along the northern border to inhibit possibilities of encroachment and infiltration.[56] The Kalapani area is likely to have been included among such areas.[57] Nepal too requested India's help in policing its northern border as early as 1950, and 17 posts are said to have been established jointly by the two countries.[58][59]