In reply to clarkie: Just be careful to be friendly to the native Chechuans of you are camping in or near their villages on the way round. it's their home after all.
They are a nice group and welcome some nice Western delicacies such as fresh fruit, energy bars etc. The kids always want sweets from you but it's better to give them dried fruit for their health. Dentists aren't a huge presence in the mountains.
Also, when I was there, a good few years ago now admittedly, there were bandits coming over the pass from their drug growing fields and holding 'tourists' up at gun point! A german guy was shot dead for refusing to give them his backpack the year before I was there. By being nice to the locals they offered to escort us over the worst pass - with rifles - and it certainly eased our worries about the bandits. And they were godd company and we learned from them. - sterilise ALL water.
Also, dogs there, attached to mountain dwellings, can be fierce and if you come across any ( you most likely will) steer well clear if possible and don't engage with them!! They WILL defend their territory. Other than all that - enjoy. It's very beautiful.