The flock leaves before first light, four hundred sheep and goats moving uphill in a single grey shape, with two dogs working the edges and a man in a woollen chola walking behind.

For centuries Gaddi families have spent the winter in the lower Kangra valley and the summer on the high pastures beyond the Dhauladhar, crossing passes above 4,000 metres twice a year.

The route has not changed much. The families have. Of the six brothers in one household we walked with, only one still goes up with the flock; the others drive taxis in Dharamshala or work in Chandigarh.

"The grass is the same, the pass is the same," the eldest said at the top of the first climb. "What is different is who is walking."

The forest department now issues grazing permits online. The shepherds carry phones, and on a clear day at the pass there is signal. Most of them say the walk is still the best part of the year.