Where did our local hero Joseph Hooker travel to ?

In this area of Sikkim in the lower Himalayas he travelled on foot and sometimes barefoot climbing up to the very high passes braving tigers, crocodiles, leeches, ticks, biting flies, snakes, cockroaches, rats giant nettles, and always measuring the temperature and atmospheric pressure measuring heights with a theodolite and collecting and drawing and preserving plants and seeds!