The fire is spreading across the building's complex roof and poses a high risk of reaching nearby buildings, Lieutenant Colonel Emmanuel Viaud of the Savoie Fire and Rescue Service told AFP at around 10pm.
Firefighters are struggling to bring the blaze under control as the roof is buried under a thick layer of snow, making it difficult to locate "smoke vents", Mr Viaud said more than two hours after the fire broke out. "There are no casualties at this time," he added.
Hotel management confirmed that everyone had been accounted for. The cause of the fire remains unclear.
Eliana Nunes