They were part of a group of four hiking towards the 2,867-metre high Juferhorn peak in the eastern canton of Grisons when they were buried in snow, a statement said.
The hikers, aged from 23 to 53, were properly equipped. The youngest was able to free himself and pulled a fellow climber out. The two others, a man aged 53, and a woman, 50, were dug out by rescuers.
The man died in the snow before he was found while the woman succumbed to her injuries after being hospitalised in critical condition.