The 17-year-old was injured while longboarding in the 6800 block of Isleview Road near Horseshoe Bay around 6 p.m. PT, according to a statement released by West Vancouver police on Monday morning.
A woman working at a nearby construction site said she did not see the teen fall, but saw the teen catching a ride on the bumper of the van just beforehand.
She rushed to the scene after hearing screaming, and said she saw that the youth was not wearing a helmet. Another worker at the site rushed to a nearby house to grab a towel to bandage the youth's head until an ambulance arrived.
The injured youth was rushed to hospital with critical head injuries and remains in intensive care.
West Vancouver police Const. Jeff Palmer wouldn't confirm if the teen was bumper riding, or skitching, and said the cause of the accident remains under investigation.
"We have different understandings of how the accident occurred so we're going to reserve public comment subject to further investigation," he said.
The driver and a second longboarder who was at the scene have been cooperating with investigators, and no charges have been recommended at this point, said Palmer.
The teen's name has not been released but police say all three involved are friends and school classmates from Rockridge Secondary School. A critical incident counselling team has been sent to the school.
Longboarding is a form of skateboarding in which riders descend steep hills using skateboards designed for the high-speed turns.
In July 2010 a woman in her 20s died while longboarding down Mount Seymour Road in North Vancouver when she collided with a van.