The group of three Dutch snowboarders in their twenties were off-piste on Tuesday when they were swept away in the Valfrejus resort, mountain rescue services from the area said in a statement.
One of them has been confirmed dead while the two others are still missing.
"Initial information suggests the three people did not have detection equipment," it said, referring to systems that allow rescuers to locate skiers stuck beneath the surface.
A helicopter and sniffer dogs were deployed Wednesday morning to try to find the two missing people.
In a separate incident near the Vars and Risoul resorts, a skier was killed on Tuesday in an avalanche, local officials confirmed without giving further details.
Heavy snowfall in recent days have made off-piste areas particularly treacherous, with the avalanche risk evaluated at four on a scale of five by the French weather office on Tuesday.
A major avalanche also swept over a slope in the high-altitude resort of Tignes, sending people fleeing for safety. No injuries were reported, though dozens were left shocked by the experience.