MALANG, India  Buddhi Devi was 14 when she was betrothed. In India, that is not unusual: many marry young. Her intended was a boy from her village who was two years younger  that, too, was not strange. But she was also supposed to marry her future husband’s younger brother, once he was old enough.

Now 70 and a widow who is still married one of her husbands is dead  Ms. Devi is a ghost of another time, one of a shrinking handful of people who still live in families here that follow the ancient practice of polyandry. In the remote villages of this Himalayan valley, polyandry, the practice of multiple men marrying one wife, was for centuries a practical solution to a set of geographic, economic and meteorological problems.

People here survived off small farms hewed from the mountainsides at an altitude of 11,000 feet, and dividing property among several sons would leave each with too little land to feed a family. A harsh mountain winter ends the short planting season abruptly. The margin between starvation and survival is slender.

“We used to work and eat,” Ms. Devi said, her face etched by decades of blistering winters, her fingers thick from summers of tilling the soil. “There was no time for anything else. When three brothers share one lady, they all come back to one house. They share everything.”