RCMP Cpl. Thomas Blakney says three pickup trucks and one car were involved in the Friday afternoon accident at Canyon Hot Springs, near Revelstoke.
He says police don't yet know what caused the crash that left the two women dead and another man in critical condition.
No names have yet been released because Blakney says police are trying to determine the victims' identities and contact their families.
He says the highway is closed, and motorists will be stopped in Golden and Revelstoke and should check the Ministry of Transportation's DriveBC website for updates.