RCMP say the single-vehicle crash happened Tuesday afternoon near Smoky Lake, Alta.
They say the van, driven by a 21-year-old man from Oregon, hit the ditch to avoid colliding with a semi trailer.
None of the injuries are believed to be life-threatening but one 18-year-old female sustained severe head lacerations.
Others suffered broken bones and cuts.
RCMP say the van was heading to Edmonton in preparation for a wedding later this week.
Several of the occupants were from Plamondon, Alta., while others were from Oregon or Alaska.
The driver of the van has been charged with attempting to pass unsafely.
Alcohol was not a factor but the fact many of the passengers weren't wearing seat belts may have contributed to the high number of injuries.