 In 1968, he became one of the first foreigners to cross Bhutan and study its little-known eastern districts.He then made the first detailed study of the Kingdom of Zanskar in Kashmir, later studying the Minaro (Dards) of Baltistan and Ladakh, while attempting to locate precisely the "land of the gold digging ants" of Herodotus.In 1973, he crossed the Himalayas by hovercraft, between Mounts Annapurna and Dhaulaghiri.