Borasu Pass Trek A challenging 7 8 day trek linking Uttarakhand and Himachal, covering 64 km up to 5,450 m. The trail crosses Har Ki Dun valley, glaciers, and high mountain passes with views of Swargarohini peaks. Best time May to June and September to October. https://www.thinairexpedition.com/badasu-pass-trek/