Police were called to Pemberton Meadows Road just after 11 a.m. Sunday, after a truck with five people lost control, went off-road and flipped.
"When it rolled, it ejected at least one person,” said Sgt. Rob Knapton with Whistler RCMP.
One person died at the scene. Two people were taken via air ambulance to Vancouver General Hospital, and two to a Whistler clinic, he said.
Knapton says the truck barely missed a large group of cyclists who were participating in the village's annual Slow Food Cycle event.
"This could have been way worse, we're just thankful it didn't turn out worse than it did."
Knapton says the five people in the truck were coming back from an all-night party in Pemberton called the Two-Acre Shaker.
Police are looking into speed and alcohol as possible factors.