Do you still recommend trekking in Upper Mustang, with all the new road construction?

It's true that there has been significant road building in Upper Mustang over the past few years. The government intends to continue upgrading the road to make this one of the key border crossings to Tibet. These roads have a significant impact on the culture and environment of Upper Mustang and they've had a very negative impact on trekking in parts of Upper Mustang. The road, though far from busy, has regular truck traffic along it and the dust these vehicles kick up doesn't make for a pleasant trekking experience, plus the character of roadside villages has changed dramatically.

However: this only affects the western side of the river valley. On the eastern side of the valley there is currently no road construction and life carries on in much the way it has been for years. Trekking routes here are quiet and unaffected by vehicle traffic whereas the villages remain small and traditional. There are many routes you can do on the eastern side of the valley to villages, caves and monasteries and the scenery is great.

Personally, I would not pay for an Upper Mustang permit if I were only going to trek the western side, but I would certainly pay for it to trek the eastern side. In my opinion the best option is to drive up the western side of the valley to Lo Manthang and then slowly walk down the eastern side. You'd also want a few days exploring side valleys and areas to the north, east and west of Lo Manthang. If you do this then Upper Mustang is as good as it has always been.