@clanger_88
I was thinking of doing the Inderhara Pass to Chamba, or something similar. Maybe 5/6 nights.
Sure.
This map might be interesting to you - apart from the usual zoom functions you'll see a 3D and panning options in the bottom right hand corner of the screen.
I have contacted several companies about the trek. The only one to have got back in touch with me say there are no scheduled treks but if I would want to trek alone they would arrange it for me. Is this something worth booking in advance or should I do this when I arrive?
Okay, first thing to note here is that Indians are notorious for not responding to emails. If you really want contact, you'll need to pick up the phone.
Secondly, I'm sympathetic to booking in advance, whether whilst still at home, or when you land in Delhi. At the very least I would want to know about fixed / scheduled / guaranteed departures.
Lastly, and without exhausting all of the options, have you checked with:
http://www.summit-adventures.net/inderahara-pass-trek-to-chamba.html
http://www.dharamsalatreks.com/trek-to-chamba-over-indrahar-pass/
Good luck!
