Darchula, Nov. 13 -- As Nepal celebrated Tihar festival earlier this week, families across the country were preparing to reunite, decorate their homes with garlands of marigold and globe amaranth flowers, and exchange colourful tika. Even those who had been unable to return to their villages for Dashain were making plans to go home.

But for Anjani Bohara of Chhangru, a village on Nepal's northwestern edge, the festive season was a time to leave home.

Before her family could move out, it had to store its harvest and make preparations for six months away. "There's so much to do before we leave. We have to get everything in order, both at home and on the farm," she said last week.

Her 13-member family was busy gathering firewood, cutting ...