Complex sentence: Unlike most maps, the expedition's report shows this summit as being in Tibet and the Tibet-Bhutan border is shown crossing the summit of Gangkhar Puensum, described as "the highest peak in Bhutan", at 7570 metres.
Split into simpler sentences: Unlike most maps, the expedition's report shows this summit as being in Tibet. The Tibet-Bhutan border is shown crossing the summit of Gangkhar Puensum, described as "the highest peak in Bhutan", at 7570 metres.