Baato – “the path” in Nepali – is the extraordinary journey taken annually by villagers living in rural Nepal, as they transport huge bundles of medicinal herbs to the city of Dharan for sale. Following a tradition that has existed for more than a century, Mikma and her family cover a distance of 300 miles by foot over five arduous days. Wrapped around steep and rocky mountains, the trails are treacherous and gruelling, while the obstacles they face are more than physical: they have to deal with administrative hassle, corruption and infrastructure development.

Closely following this resilient group of travellers – which largely consists of women carrying enormous loads on their shoulders with astonishing ease – the film draws a striking contrast between the scenery of Nepali highlands and the intimate dynamics of Mikma’s family. As they take the occasional breaks for food and rest, their spirited conversations attest to the growing tension between tradition and modernity. The absence of young men on these annual treks is a prime example of this tug-and-pull; many have left the village for a brighter economic future elsewhere.

More than a family portrait, Lucas Millard and Kate Stryker’s film also widens its scope to take in the complex geopolitics of Nepal. The generational shifts are not only felt within the community, but also embedded in the changing landscapes that surround the villagers. The (very) slow construction of a new highway promises greater accessibility to metropolitan areas and new employment opportunities, but the project comes with the threat of displacement and inadequate compensation for rural dwellers.

• Baato is released on 28 July in UK cinemas.